MailMan

Set this property to true to request that the currently running operation be aborted.

This applies to methods that may take time to complete, such as methods that perform network communication or lengthy file operations. Methods that always complete quickly are generally not affected.

If no method is currently running, the property is automatically reset to false when the next method call begins. When an abort actually occurs, Chilkat resets this property to false.

Both synchronous and asynchronous method calls can be aborted. A synchronous method can be aborted by setting this property from another thread.

Determines whether an email should be sent when one or more recipients are rejected by the SMTP server.

The default value is false, which means Chilkat continues sending even if some recipients are rejected.

When set to true, the email is not sent to any recipients if the SMTP server rejects any recipient address.

Important: This property only works when SMTP pipelining is disabled. Because SmtpPipelining is true by default, set SmtpPipelining = false when all-or-none behavior is required.

Note: SMTP servers do not always verify recipient addresses. Even when they do, the server can usually verify only addresses within domains it controls.

Controls whether Chilkat automatically selects the SMTP and POP3 TLS mode from a standard port number when a connection is prepared.

• SMTP port 465: implicit TLS (SmtpSsl = true).
• SMTP port 587: explicit TLS using STARTTLS.
• SMTP port 25: no TLS is implied.
• POP3 port 995: implicit TLS (PopSsl = true).
• POP3 port 110: no TLS is implied.

The default value is true. For these standard ports, Chilkat sets the related TLS properties to a consistent combination before connecting, so conflicting implicit and explicit TLS settings do not remain in effect.

If the configured port is nonstandard, AutoFix does not change the TLS properties. The application must set the desired implicit, required-explicit, opportunistic-explicit, or unencrypted mode explicitly.

Important: AutoFix is applied when Chilkat prepares the connection. Assigning a port number does not immediately rewrite the visible property values.

Determines whether Chilkat automatically generates a unique Message-ID header when an email is sent.

The default behavior is to generate a new unique Message-ID at send time. This allows the same Email object to be reused without accidentally sending duplicate message IDs.

If duplicate message IDs are used, some SMTP servers may treat the message as a duplicate and discard it.

When automatic generation is enabled, calling GetHeaderField("Message-ID") before sending will not necessarily show the actual message ID that Chilkat sends.

Set this property to false to prevent Chilkat from automatically generating the Message-ID header.

When true, Chilkat automatically sends the SMTP RSET command before sending a new email over an already-open SMTP connection.

This helps ensure the SMTP session is in a clean state before the next email is sent.

The default value is false.

Note: This property only applies when reusing an existing SMTP connection.

Determines whether Chilkat automatically unwraps digitally signed or encrypted email when the message is downloaded or loaded from MIME.

The default value is true. When enabled, Chilkat verifies signatures and decrypts encrypted content when possible. The results are made available through the email object's security-related properties and methods.

Set this property to false if you want signed or encrypted attachments, such as .p7m or .p7s files, to remain as ordinary attachments.

Important: Signature verification and decryption must occur when the original MIME is first loaded. After MIME is parsed into Chilkat's internal email object format, the exact original MIME bytes are no longer available, and the signature can no longer be verified.

Sets the local IP address to use when connecting from a computer that has multiple network interfaces or multiple IP addresses.

For most computers, this property should be left unset. Chilkat will automatically use the default local IP address.

The value should be a numeric IP address, such as 165.164.55.124, not a hostname.

Contains a numeric code describing the result of the last connection attempt. This applies to the last connection made, or attempted, by any method.

The maximum number of seconds to wait while attempting to connect to an SMTP or POP3 server.

The default value is 30 seconds.

If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.

Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.

Possible causes of hangs include:

• A timeout property set to 0, indicating an infinite timeout.
• A hang occurring within an event callback in the application code.
• An internal bug in the Chilkat code causing the hang.

The DsnEnvid property specifies the SMTP DSN ENVID value, which is an arbitrary identifier attached to the SMTP envelope. The same value is typically returned in DSN responses so the sending application can correlate delivery notifications with the original outbound email.

Common choices for DsnEnvid include:

• An internal message ID:

  MSG-10004521

• A GUID or UUID:

  550e8400-e29b-41d4-a716-446655440000

• An order or transaction number:

  ORDER-847291

• A timestamp-based identifier:

  MAIL-20260515-153045-001

• A composite identifier combining application, customer, and message IDs:

  billing|cust-9182|invoice-44381

The value should uniquely identify the outbound email within your application. It does not need to match the MIME Message-ID header, although some applications choose to use the same identifier for both.

About SMTP DSN

SMTP DSN means Delivery Status Notification. It is an optional SMTP service extension defined by RFC 3461 that allows the sender to request delivery-status reports from the SMTP server.

DSN allows an application to request notifications such as:

• Successful delivery
• Delivery failure
• Delayed delivery

It also allows the sender to specify whether the returned notification should include the full original message or only the message headers.

In MailMan, DSN behavior is controlled using:

• DsnEnvid — sets the SMTP ENVID envelope identifier.
• DsnNotify — controls when notifications are requested, such as SUCCESS, FAILURE, DELAY, or NEVER.
• DsnRet — controls whether DSN responses include the full message or only headers.

DSN is an optional SMTP extension and is not supported by all SMTP servers. A server supports DSN only if it advertises the DSN capability in response to the SMTP EHLO command.

The IsSmtpDsnCapable method can be used to determine whether the SMTP server supports DSN.

Even when DSN is supported, some SMTP servers or downstream mail systems may ignore or partially honor DSN requests.

Sets the SMTP DSN NOTIFY parameter used when sending email.

The value may be left empty, set to NEVER, or set to a comma-separated combination of SUCCESS, FAILURE, and DELAY.

Sets the SMTP DSN RET parameter used when sending email.

The value may be left empty, set to FULL to request the full message in DSN notifications, or set to HDRS to request only the message headers.

When true, Chilkat embeds the signing certificate chain in signed email.

Certificates are included up to, but not including, the root certificate. If IncludeRootCert is also true, the root CA certificate is included as well.

The default value is false

Enables automatic resolution of passwords and credentials from secure local storage.

When set to true, supported properties and methods can accept a Chilkat secret specification string instead of a literal password. Secret specification strings begin with !!.

Chilkat resolves secrets from:

• Windows Credential Manager on Windows.
• Apple Keychain on macOS.

The secret specification format is: !![appName|]service[|domain]|username

This applies to PopPassword, SmtpPassword, HttpProxyPassword, SocksPassword, PopPasswordBase64, and SshAuthenticatePw.

The default value is false.

Specifies a filter expression applied by methods such as LoadXmlFile, LoadXmlString, LoadMbx, CopyMail, and TransferMail.

When a filter is present, only emails matching the expression are returned. For TransferMail, only matching emails are removed from the mail server.

Example expressions:

Body like "mortgage rates*"
Subject contains "update" and From contains "chilkat"
To = "info@chilkatsoft.com"

Rules for filter expressions:

• Any MIME header field name may be used. Header names are case-insensitive.
• Literal strings are enclosed in double quotes.
• String matching is case-insensitive.
• The * wildcard matches zero or more characters.
• Parentheses may be used to control precedence.
• Logical operators are AND, OR, and NOT.
• String comparison operators include CONTAINS and LIKE.

Note: Filtering works on text strings only, not dates or numbers.

Sets the interval, in milliseconds, between AbortCheck event callbacks.

This allows an application to periodically decide whether a long-running operation should be aborted.

The default value is 0, which means no AbortCheck callbacks are generated.

Sets the hostname sent in the SMTP EHLO or HELO command.

The default value is an empty string, which causes Chilkat to use the local computer's hostname.

Sets the authentication method used when the configured HTTP proxy requires credentials.

Valid values are Basic and NTLM. Leave this property empty when the proxy does not require authentication.

Sets the optional Windows domain used for NTLM authentication with an HTTP proxy.

This property is ignored for Basic proxy authentication and may be left empty when no NTLM domain is required.

Sets the hostname or IP address of the HTTP proxy used for SMTP and POP3 connections.

Leave this property empty to connect directly without an HTTP proxy.

Sets the password used to authenticate with the configured HTTP proxy.

This property is used together with HttpProxyUsername and, for NTLM authentication, may also be used with HttpProxyDomain.

Sets the TCP port of the HTTP proxy.

Common proxy ports include 8080 and 3128. The value is used only when HttpProxyHostname is set.

Sets the username used to authenticate with the configured HTTP proxy.

This property is used only when the proxy requires authentication.

Determines whether pending POP3 deletion marks are committed automatically after a successful delete operation or full-message retrieval performed with keepOnServer = false.

The default value is true. Chilkat sends DELE as each message is processed. After the complete operation succeeds, Chilkat sends QUIT, commits the deletions, and closes the POP3 session. The next POP3 method automatically reconnects and establishes a new session.

When set to false, Chilkat sends DELE but leaves the session open and the deletions uncommitted. Call Pop3EndSession to send QUIT and commit them. Calling Pop3Reset, calling Pop3EndSessionNoQuit, or losing the POP3 connection before QUIT causes the server to forget the pending deletion marks.

Header-only or partial-message retrieval never marks a message for deletion, regardless of this property or the value of keepOnServer.

Determines whether the root CA certificate is included in the S/MIME signature of a signed email.

This property only applies when EmbedCertChain is true.

Returns true if Chilkat believes the POP3 connection is still open.

Accessing this property does not send any command to the POP3 server. If the server has disconnected but Chilkat has not yet attempted further communication, this property may still return true.

To verify that the POP3 connection is actually alive, call Pop3Noop.

Returns true if Chilkat believes the SMTP connection is still open.

Accessing this property does not communicate with the SMTP server. A lost connection may not be detected until the next SMTP command is sent.

To verify that the SMTP connection is actually alive, call SmtpNoop.

Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

Indicates the success or failure of the most recent method call: true means success, false means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.

Contains the SMTP failure status code returned by the server for the most recent SMTP operation.

This property is nonzero only when Chilkat successfully connected, began an SMTP session, and then received a status code indicating failure. Such failures are generally reported by 4xx or 5xx replies.

• 4xx — Temporary failure. Retrying later may succeed.
• 5xx — Permanent failure. The request was rejected and usually requires a change before retrying.

A value of 0 means that no SMTP failure status code was received. For example, the operation may have failed before an SMTP session was established. Use SmtpFailReason and LastErrorText for additional diagnostic information.

Provides the text associated with the most recent SMTP reply received from the server.

Use this property together with LastSmtpStatus when diagnosing an SMTP failure or interpreting a server-specific response.

Specifies a local file path where Chilkat writes each message exactly as it was received from the POP3 server.

This is useful for debugging problems involving MIME structure, encodings, attachments, or server behavior.

Specifies a local file path where Chilkat writes the exact MIME message sent to the SMTP server.

This is useful for inspecting the final MIME produced by Chilkat.

Sets the POP3 server hostname or IP address.

Do not include http:// or https://. The value should be a hostname such as pop.example.com or an IPv4/IPv6 address.

Sets the POP3 server port number.

The default value is 110.

The standard POP3 ports and their associated MailMan property settings are described below.

mailman.MailPort = 995;
mailman.PopSsl = true;

mailman.MailPort = 110;
mailman.PopSsl = false;
mailman.Pop3Stls = false;
mailman.Pop3StlsIfPossible = false;

mailman.MailPort = 110;
mailman.PopSsl = false;
mailman.Pop3Stls = true;

mailman.MailPort = 110;
mailman.PopSsl = false;
mailman.Pop3StlsIfPossible = true;

Important: PopSsl and Pop3Stls represent two different approaches to TLS security:

• PopSsl = true means the connection begins as SSL/TLS from the very start (implicit TLS).
• Pop3Stls = true means the connection begins unencrypted and is later upgraded to TLS using the POP3 STLS command (explicit TLS).

These two approaches are mutually exclusive and should not both be enabled at the same time.

Modern POP3 servers most commonly use either:

• 995 with PopSsl = true, or
• 110 with Pop3Stls = true.

Limits the number of messages retrieved from the POP3 server. The following methods honor this property:

• GetAllHeaders
• GetHeaders
• FetchAll
• FetchRange

The default value is 0, which means no limit.

For FetchAll, a positive value selects the newest messages in the mailbox. For example, when MaxCount = 2, the two newest messages are retrieved and returned in normal mailbox order, with the older of the two first.

Sets the OAuth2 access token used for POP3 or SMTP XOAUTH2 authentication.

When this property is set, Chilkat uses the AUTH XOAUTH2 authentication mechanism when it is supported by the server.

For POP3 XOAUTH2 authentication: PopPassword should be left empty, or explicitly set to the empty string.

For SMTP XOAUTH2 authentication: SmtpPassword should be left unset, or set to the empty string.

The access token is sent as a bearer token during the AUTH XOAUTH2 authentication exchange.

Controls the MIME format used for digitally signed email.

When set to false, Chilkat creates a multipart/signed email. In this format, the original email content remains visible as a normal MIME body part, and the digital signature is included as a separate MIME part.

The top-level MIME Content-Type header will look similar to:

Content-Type: multipart/signed;
    protocol="application/pkcs7-signature";
    micalg=sha-256;
    boundary="------------040808030405050402070604"

This is commonly referred to as a detached signature because the signed content exists separately from the signature itself.

When set to true, Chilkat creates an opaque signed email using PKCS#7 signed-data format. In this case, the original MIME content is encapsulated inside the PKCS#7 signature structure.

The top-level MIME Content-Type header will look similar to:

Content-Type: application/pkcs7-mime;
    smime-type="signed-data";
    name="smime.p7m"; micalg=sha-256

This format is historically known as opaque signing because the original message content is wrapped inside the PKCS#7 signed object and is not directly visible as ordinary MIME body parts.

The default value is true.

Sets the filename used in the Content-Disposition header when sending a PKCS#7 encrypted email.

The default value is smime.p7m.

Sets the filename used in the Content-Disposition header when sending an opaque signed PKCS#7 email.

The default value is smime.p7m.

Sets the filename used in the Content-Disposition header when sending a signed email with a detached PKCS#7 signature.

The default value is smime.p7s.

This property is only valid in programming environments and languages that allow for event callbacks.

Sets the value that represents 100% completion for PercentDone event callbacks.

The default value is 100, meaning progress values range from 0 to 100. Setting this property to a larger value provides finer granularity. For example, setting PercentDoneScale = 1000 allows progress to be reported in tenths of a percent.

For example, if PercentDoneScale = 1000, then a callback value of 453 represents 45.3% complete.

The value is clamped to a minimum of 10 and a maximum of 100000.

Returns 0 when no POP3 session is active.

Otherwise, returns a positive integer that increments each time a new POP3 session is established. This can be used to detect whether a new session has started.

Provides the accumulated raw POP3 commands sent to the server and the raw responses received from the server.

This property is read-only. To clear it, call ClearPop3SessionLog.

Determines whether SPA, also known as NTLM authentication, is used for POP3.

Set this property to true to use SPA authentication. No other programming changes are required.

The default value is false.

Note: If SPA/NTLM authentication fails, set Global.DefaultNtlmVersion = 1 and retry.

Indicates whether the POP3 server certificate chain was successfully verified during the most recent SSL/TLS POP3 connection.

This property reports certificate-chain verification only. It does not report hostname matching or public key pinning. When either of those checks is required, a mismatch causes the connection itself to fail.

This property is meaningful only after an SSL/TLS POP3 connection attempt.

Determines whether Chilkat requires the POP3 connection to be upgraded to TLS using the STLS command.

When set to true, Chilkat initially connects without encryption and then sends STLS before authenticating. The connection fails if the server does not support the required upgrade.

PopSsl takes precedence. If implicit TLS is enabled, this property does not cause an additional explicit TLS upgrade.

The default value is false. Use Pop3StlsIfPossible when the upgrade should be attempted only when the server advertises support.

Determines whether Chilkat attempts POP3 STLS when the server advertises support for it.

If the server supports STLS, the connection is upgraded to TLS. Otherwise, the connection remains unencrypted.

PopSsl takes precedence. If implicit TLS is enabled, no separate STLS upgrade is attempted. Use Pop3Stls = true instead when encryption is required and the connection should fail if explicit TLS is unavailable.

The default value is false.

Sets the POP3 password.

On Windows, if Pop3SPA is enabled, both PopUsername and PopPassword may be set to "default" to use the credentials of the current logged-on Windows user.

Sets the POP3 password as Base64-encoded data instead of plain text.

MailMan decodes the Base64 value and uses the resulting bytes as the POP3 password. This property is useful when an application already stores or receives the password in Base64 form; Base64 encoding by itself does not provide encryption.

Determines whether implicit SSL/TLS is used when connecting to the POP3 server.

When set to true, the TLS connection is established immediately when the TCP connection is opened. Implicit POP3 TLS commonly uses port 995.

Implicit TLS takes precedence over explicit TLS. Therefore, when PopSsl = true, the settings in Pop3Stls and Pop3StlsIfPossible do not cause a separate STLS upgrade.

The default value is false. When AutoFix is enabled, a standard POP3 port can cause Chilkat to select the appropriate TLS mode automatically before connecting.

Sets the POP3 login name.

On Windows, if Pop3SPA is enabled, both PopUsername and PopPassword may be set to "default" to use the credentials of the current logged-on Windows user.

Determines whether IPv6 is preferred over IPv4 when both are available for a hostname.

The default value is false, which means IPv4 is preferred.

Sets the maximum number of seconds to wait when the SMTP or POP3 server stops responding.

The default value is 30 seconds.

Determines whether the hostname used for the TLS connection must match a name in the server certificate's Subject Alternative Name (SAN) extension.

The comparison is made against the SNI hostname sent in the TLS handshake. MailMan normally uses the configured server hostname. When connecting by IP address or through an alternate endpoint, set SniHostname to the expected DNS hostname.

Hostname matching is enforced independently of RequireSslCertVerify. Therefore, it still occurs when certificate-chain verification is not required.

The default value is false.

Determines whether Chilkat requires the SMTP or POP3 server certificate chain to be successfully verified for an SSL/TLS connection.

When set to true, Chilkat rejects the connection if the certificate is expired, is not yet valid, or its chain/signature cannot be verified to a trusted root.

Certificate-chain verification is separate from hostname matching and public key pinning. RequireHostnameMatch is enforced independently, even when this property is false. TlsPinSet supplements, rather than replaces, certificate verification.

The default value is false. This property applies only to SSL/TLS connections.

Determines whether the email's Date header is reset to the current date and time when an email is loaded.

This applies to methods such as LoadMbx, LoadEml, LoadMime, LoadXml, and LoadXmlString.

The default value is false.

Sets the buffer size used by the underlying TCP/IP socket when sending data.

The default value is 32767.

Sets the maximum message size, in bytes, for POP3 operations that can download one or more complete emails. It applies to any method capable of downloading a full email and does not restrict header-only or partial-body retrieval.

The default value is 0, which means no size limit.

For multi-message retrieval, a message larger than the limit is omitted from the result. No placeholder Email is added for the skipped message, and skipping an oversized message does not by itself cause the retrieval method to fail.

Sets the SMTP authentication method to use.

This property should usually be left empty so Chilkat can automatically choose the most secure method advertised by the SMTP server.

If the server does not advertise authentication methods, or if a specific method must be forced, set this property to one of: NONE, LOGIN, PLAIN, CRAM-MD5, or NTLM.

Note: If NTLM authentication fails, set Global.DefaultNtlmVersion = 1 and retry.

Contains a keyword describing the result or failure reason for the last SMTP operation.

Sets the SMTP server hostname or IP address.

Do not include http:// or https://. The value may be a hostname, IPv4 address, or IPv6 address.

Sets the Windows domain to use when logging in to an SMTP server with NTLM authentication.

Leave this property empty if no domain is required.

Sets the SMTP envelope sender address used in the MAIL FROM command.

This address receives bounce messages and identifies the originator of the SMTP transaction. It may differ from the From MIME header.

If left empty, Chilkat uses the email address from the message's From header.

SMTP servers may reject the envelope sender based on DNS, SPF, or other server policy checks.

Sets the password used for SMTP authentication.

Chilkat supports SMTP authentication methods such as LOGIN, PLAIN, CRAM-MD5, and NTLM, and normally chooses the most secure available method automatically.

If NTLM authentication is used, SmtpUsername and SmtpPassword may be set to the keyword "default" to use the current Windows logged-on credentials.

Determines whether SMTP pipelining is used when the server advertises support for it.

The default value is true.

Set this property to false to prevent SMTP pipelining. This is required when using AllOrNone.

Sets the SMTP server port.

The default value is 25. If using implicit SSL/TLS with SmtpSsl = true, the common port is 465.

Provides the accumulated raw SMTP commands sent to the server and raw responses received from the server.

This property is read-only. To clear it, call ClearSmtpSessionLog.

Determines whether Chilkat uses implicit SSL/TLS when connecting to the SMTP server.

When set to true, the TLS connection is established immediately when the TCP connection is opened. Implicit SMTP TLS commonly uses port 465.

Implicit TLS takes precedence over explicit TLS. Therefore, when SmtpSsl = true, the settings in StartTLS and StartTLSifPossible do not cause a separate STARTTLS upgrade.

The default value is false. When AutoFix is enabled, a standard SMTP port can cause Chilkat to select the appropriate TLS mode automatically before connecting.

Indicates whether the SMTP server certificate chain was successfully verified during the most recent SSL/TLS SMTP connection.

This property reports certificate-chain verification only. It does not report hostname matching or public key pinning. When either of those checks is required, a mismatch causes the connection itself to fail.

This property is meaningful only after an SSL/TLS SMTP connection attempt.

Sets the username used for SMTP authentication.

If SmtpAuthMethod is NTLM, SmtpUsername and SmtpPassword may be set to the keyword "default" to use the current Windows logged-on credentials.

Specifies the DNS hostname sent in the Server Name Indication (SNI) extension of the TLS handshake for SMTP and POP3 connections.

Normally this property is left empty. In that case, MailMan uses SmtpHost for SMTP connections and MailHost for POP3 connections.

Set this property when connecting by IP address or through an alternate endpoint while the server's TLS certificate and virtual-host configuration use a DNS hostname. The value is also used for certificate hostname comparison when RequireHostnameMatch is true.

The default value is the empty string.

Sets the SOCKS4 or SOCKS5 proxy hostname or IPv4 address.

This property is used only when SocksVersion is set to 4 or 5.

Sets the SOCKS5 proxy password, if authentication is required.

SOCKS4 does not use passwords, so this property applies only to SOCKS5.

Sets the SOCKS proxy port.

The default value is 1080. This property applies only when SocksVersion is set to 4 or 5.

Sets the SOCKS4 or SOCKS5 proxy username.

This property is used only when SocksVersion is set to 4 or 5.

Specifies whether a SOCKS proxy is used.

• 0 — no SOCKS proxy is used. This is the default.
• 4 — connect through a SOCKS4 proxy.
• 5 — connect through a SOCKS5 proxy.

Sets the socket receive buffer size.

The default value is 4194304.

This property should normally be left unchanged. It may be increased if download performance is slow. Values should preferably be multiples of 4096.

Sets the socket send buffer size.

The default value is 262144.

This property should normally be left unchanged. It may be increased if upload performance is slow. Testing values such as 512K or 1MB is reasonable. Values should preferably be multiples of 4096.

Sets the TLS cipher suites Chilkat is allowed to offer when establishing SSL/TLS connections.

The default value is an empty string, meaning Chilkat may offer all implemented cipher suites. To restrict the allowed ciphers, set this property to a comma-separated list of cipher suite names, ordered by preference.

The cipher suites supported by Chilkat are:

Important: The client offers a list of allowed cipher suites, but the server chooses the final cipher suite from that list.

This property can also include special keywords:

• rsa1024 — reject server certificates with RSA keys smaller than 1024 bits.
• rsa2048 — reject server certificates with RSA keys smaller than 2048 bits.
• secure-renegotiation — require secure renegotiation as defined by RFC 5746.
• best-practices — use Chilkat's current best-practice cipher policy.

The best-practices setting currently requires RSA server keys of at least 1024 bits, requires secure renegotiation, and disallows RC4, DES, and 3DES ciphers.

Example:

TLS_DHE_RSA_WITH_AES_256_CBC_SHA256, TLS_RSA_WITH_AES_256_CBC_SHA, rsa1024, secure-renegotiation

Selects the SSL/TLS protocol version used for secure SMTP and POP3 connections.

Possible values include:

• default
• TLS 1.3
• TLS 1.2
• TLS 1.1
• TLS 1.0
• SSL 3.0
• TLS 1.3 or higher
• TLS 1.2 or higher
• TLS 1.1 or higher
• TLS 1.0 or higher

The default value is default, which allows Chilkat to choose the protocol dynamically based on the server's requirements.

Choosing an exact protocol version can cause the connection to fail unless that exact version is negotiated. In most cases, using an or higher setting is preferable.

Determines whether Chilkat requires SMTP STARTTLS.

When set to true, Chilkat connects to the SMTP server normally and then sends the STARTTLS command to upgrade the connection to TLS before authenticating and sending email. The connection fails if the server does not support the required upgrade.

SmtpSsl takes precedence. If implicit TLS is enabled, this property does not cause an additional explicit TLS upgrade.

The default value is false. Use StartTLSifPossible when the upgrade should be attempted only when the server advertises support.

This property applies to SMTP only, not POP3.

Determines whether Chilkat attempts SMTP STARTTLS when the server advertises support for it.

If the server supports STARTTLS, the connection is upgraded to TLS. Otherwise, the connection remains unencrypted.

SmtpSsl takes precedence. If implicit TLS is enabled, no separate STARTTLS upgrade is attempted. Use StartTLS = true instead when encryption is required and the connection should fail if explicit TLS is unavailable.

The default value is true. This property applies to SMTP only, not POP3.

Contains the current or most recently negotiated TLS cipher suite.

If no TLS connection has been established, or if the TLS connection attempt failed, this property is empty.

Example value:

TLS_DHE_RSA_WITH_AES_256_CBC_SHA256

Sets the expected Subject Public Key Info (SPKI) fingerprints for TLS public key pinning.

During the TLS handshake, Chilkat compares the server certificate's public key fingerprint against this pin set. If none of the pins match, the connection fails.

Pinning supplements normal certificate-chain verification; it does not replace it. A matching pin does not by itself make an expired or otherwise invalid certificate acceptable.

The format is:

hash_algorithm, encoding, SPKI_fingerprint_1, SPKI_fingerprint_2, ...

Example with one SHA-256 Base64 pin:

sha256, base64, lKg1SIqyhPSK19tlPbjl8s02yChsVTDklQpkMCHvsTE=

Example with two SHA-256 Base64 pins:

sha256, base64, 4t37LpnGmrMEAG8HEz9yIrnvJV2euVRwCLb9EH5WZyI=, 68b0G5iqMvWVWvUCjMuhLEyekM5729PadtnU5tdXZKs=

Supported hash algorithms include sha1, sha256, sha384, sha512, md2, md5, haval, ripemd128, ripemd160, ripemd256, and ripemd320.

Supported encodings include base64, hex, and other Chilkat-supported encodings.

Contains the current or most recently negotiated TLS protocol version.

If no TLS connection has been established, or if the TLS connection attempt failed, this property is empty.

Possible values include SSL 3.0, TLS 1.0, TLS 1.1, TLS 1.2, and TLS 1.3.

Provides a comma-separated list of uncommon option keywords.

This property defaults to an empty string and should normally remain empty.

• ProtectFromVpn — introduced in v9.5.0.80. On Android, bypasses any installed or active VPN.
• SmtpLoginAnsi — introduced in v9.5.0.97. Causes SMTP login and password strings containing non-ASCII characters to be sent using ANSI encoding instead of UTF-8. This restores the older Chilkat behavior for SMTP servers that expect ANSI credentials.

Determines whether Chilkat automatically uses APOP authentication when the POP3 server supports it.

The default value is false.

If set to true, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is false. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

Version of the component/library, such as "10.1.0"

Adds a PFX/PKCS#12 certificate store to the MailMan object's internal list of sources used for locating certificates and private keys.

bd is a BinData object containing the bytes of a .pfx or .p12 file.

The added PFX source is searched when Chilkat needs a certificate and private key for operations such as:

• Decrypting S/MIME encrypted email
• Creating digitally signed email

Multiple PFX sources can be added by calling this method once for each PFX.

On Windows, the registry-based Windows certificate stores are automatically searched when locating certificates and private keys. Therefore, if the required certificate and private key are already installed in the Windows certificate store, explicitly adding a PFX source is often unnecessary.

On macOS, the Apple Keychain is also searched automatically. If the required certificate and private key are already available in the Apple Keychain, it is likewise unnecessary to explicitly add a PFX source.

password specifies the password required to open the PFX.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Adds a PFX/PKCS#12 file to the MailMan object's internal list of sources used for locating certificates and private keys. The pfx_file_path argument is the path to a .pfx or .p12 file.

The added PFX source is searched when Chilkat needs a certificate and private key for operations such as:

• Decrypting S/MIME encrypted email
• Creating digitally signed email

Multiple PFX sources can be added by calling this method once for each PFX.

On Windows, the registry-based Windows certificate stores are automatically searched when locating certificates and private keys. Therefore, if the required certificate and private key are already installed in the Windows certificate store, explicitly adding a PFX source is often unnecessary.

On macOS, the Apple Keychain is also searched automatically. If the required certificate and private key are already available in the Apple Keychain, it is likewise unnecessary to explicitly add a PFX source.

The password argument specifies the password required to open the PFX.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Returns the number of messages currently available in the POP3 mailbox. Returns -1 if an error occurs.

If no POP3 session is active, Chilkat connects and authenticates automatically. After a successful call, the POP3 session remains open and can be reused by subsequent POP3 methods. Call Pop3EndSession or Pop3EndSessionNoQuit to end it.

If this method fails, use VerifyPopConnection to test basic connectivity and VerifyPopLogin to test authentication.

Clears the current contents of the Pop3SessionLog property.

Clears the current contents of the SmtpSessionLog property.

Explicitly closes the current SMTP connection. Before closing the socket connection, Chilkat sends the SMTP QUIT command to the server.

Calling this method is optional in most applications. The MailMan object automatically opens an SMTP connection when an email-sending method is called and no connection is already open. The connection is then kept open so subsequent sends can reuse it. For example, if an application calls SendEmail ten times, the first call opens the SMTP connection, and the following calls send over the same connection.

If an SMTP-related property changes, such as the hostname, username, password, port, or SSL/TLS settings, the existing connection is closed and a new connection is established the next time an email-sending method is called.

The SMTP connection is also closed automatically when the MailMan object is destroyed.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Deletes POP3 messages by using the UIDLs stored in the X-UIDL headers of the Email objects in email_bundle. An email that does not contain an X-UIDL header is skipped.

Chilkat processes the bundle and marks each located message with DELE. If a connection failure occurs before processing is complete, the POP3 session is lost and all uncommitted deletion marks are forgotten.

If ImmediateDelete is true, which is the default, Chilkat sends a single QUIT after the entire bundle has been processed. This commits all deletion marks and closes the POP3 session. If it is false, the marks remain pending until the application calls Pop3EndSession.

When making multiple deletion calls, it is usually more efficient to set ImmediateDelete to false, perform all deletion operations, and call Pop3EndSession once at the end.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Marks an email for deletion by its POP3 message number.

Important: Message numbers are specific to a single POP3 session and can change from one session to the next. For example, if a mailbox contains ten messages, they are numbered 1 through 10. If message 1 is deleted and a new POP3 session is opened, the remaining messages are renumbered 1 through 9.

A POP3 session must already be established before this method is called, either explicitly by calling Pop3BeginSession or implicitly by calling another method that opens the session. This method does not automatically begin a new session because doing so could change the message numbers and cause the application to delete a different message than intended.

This method only marks the message for deletion. The message is not removed from the POP3 mailbox until the session is ended by calling Pop3EndSession, which sends the QUIT command.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Marks the POP3 message identified by the UIDL in uidl for deletion. UIDLs are preferred over message numbers because they remain stable across sessions while the message remains in the mailbox.

If ImmediateDelete is true, which is the default, Chilkat sends QUIT, commits the deletion, and closes the session before returning. If it is false, the message is only marked with DELE; call Pop3EndSession to commit all pending deletions.

Pop3Reset or Pop3EndSessionNoQuit cancels uncommitted deletion marks.

If no POP3 session is active, Chilkat connects and authenticates automatically.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Deletes a POP3 message by using the UIDL stored in the X-UIDL header of the Email in email. If email does not contain an X-UIDL header, the method fails.

If no POP3 session is active, Chilkat connects and authenticates automatically. The UIDL is used to locate the corresponding message in the current mailbox.

If ImmediateDelete is true, which is the default, Chilkat marks the message for deletion, sends QUIT to commit the deletion, and closes the POP3 session before returning. If it is false, the message is marked with DELE and the deletion remains pending until Pop3EndSession sends QUIT.

Pop3Reset or Pop3EndSessionNoQuit cancels uncommitted deletion marks. Uncommitted marks are also forgotten if the POP3 connection is lost before QUIT is sent.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Marks the POP3 messages whose UIDLs are listed in st_uidls for deletion.

Chilkat processes the UIDL set and sends DELE for each located message. If a connection failure occurs before processing is complete, the POP3 session is lost and all uncommitted deletion marks are forgotten.

If ImmediateDelete is true, which is the default, Chilkat sends a single QUIT after the entire set has been processed. This commits all deletion marks and closes the POP3 session. If it is false, the marks remain pending until the application calls Pop3EndSession.

When making multiple deletion calls, it is usually more efficient to set ImmediateDelete to false, perform all deletion operations, and call Pop3EndSession once at the end.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Retrieves messages from the POP3 mailbox and appends them to the EmailBundle in bundle. Existing emails in bundle are preserved.

If headers_only is true, Chilkat retrieves the message headers and a partial body. num_body_lines specifies the number of body lines; a value of 0 retrieves the first body line. Attachments are not downloaded. If headers_only is false, Chilkat retrieves the complete messages, including attachments.

If keep_on_server is true, every retrieved message remains on the POP3 server, regardless of ImmediateDelete.

If keep_on_server is false and complete messages are retrieved, Chilkat sends DELE for each message after it is downloaded. If ImmediateDelete = true, Chilkat sends QUIT only after the entire requested set has been downloaded successfully; this commits the deletions and closes the POP3 session. If ImmediateDelete = false, the deletion marks remain pending in the open session until the application calls Pop3EndSession.

If the POP3 connection is lost before QUIT, the session ends and the server forgets all uncommitted deletion marks. Chilkat automatically reconnects and establishes a new session when the next POP3 method is called.

Header-only or partial retrieval never marks messages for deletion, regardless of keep_on_server or ImmediateDelete.

MaxCount can limit the result to the newest messages. SizeLimit can omit oversized messages from full-message retrieval.

If an error occurs while retrieving multiple messages, processing stops at the first failure. Messages that were successfully retrieved before the failure remain appended to the output EmailBundle; Chilkat does not remove those results or restore the bundle to its prior state.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Retrieves one message by UIDL and stores it in the Email in email. The message remains on the POP3 server.

If header_only is true, Chilkat retrieves the headers and a partial body. num_body_lines specifies the number of body lines; a value of 0 retrieves the first body line. Attachments are not downloaded. If header_only is false, Chilkat retrieves the complete message, including attachments.

If uidl is not found or the fetch otherwise fails, email is left unchanged.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Downloads the complete version of the header-only or partial Email in partial_email and stores it in full_email. The full result includes the complete body and any attachments.

partial_email must retain the UIDL needed to locate the same message in the POP3 mailbox. The original POP3 session is not required; Chilkat connects and authenticates automatically when a session is not already active.

If the UIDL no longer exists in the mailbox, or if the full message cannot be downloaded for another reason, the method fails and full_email remains unchanged.

This method is useful when an application first retrieves headers or partial bodies and downloads the complete message only after the user selects it.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Fetches an email from the POP3 server by UIDL and stores the raw MIME source bytes in mime_data.

Chilkat clears the existing contents of mime_data before attempting the download. If the method succeeds, mime_data contains the downloaded MIME bytes. If it fails, mime_data remains empty.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Retrieves an email by POP3 message number and stores the raw MIME source bytes in bd.

Chilkat clears the existing contents of bd before attempting the download. If the method succeeds, bd contains the downloaded MIME bytes. If it fails, bd remains empty.

Important: Message numbers are specific to a single POP3 session and can change from one session to the next. For example, if a mailbox contains ten messages, they are numbered 1 through 10. If message 1 is deleted and a new POP3 session is opened, the remaining messages are renumbered 1 through 9.

A POP3 session must already be established before this method is called, either explicitly by calling Pop3BeginSession or implicitly by calling another method that opens the session. This method does not automatically begin a new POP3 session because doing so could change the message numbers.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Retrieves one message by POP3 message number and stores it in the Email in email. The first message has number 1. The message remains on the server.

If header_only is true, Chilkat retrieves the headers and a partial body. num_body_lines specifies the number of body lines; a value of 0 retrieves the first body line. Attachments are not downloaded. If header_only is false, Chilkat retrieves the complete message, including attachments.

If the message number is invalid or the fetch otherwise fails, email is left unchanged.

POP3 message numbers are specific to the current mailbox state and can change between sessions. Use UIDLs when a message must be identified reliably across sessions.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Retrieves a range of messages from the POP3 mailbox and appends them to the EmailBundle in bundle. Existing emails in bundle are preserved.

start_index and end_index are zero-based, inclusive indexes in the server's current mailbox order. The messages are appended in increasing index order. If end_index extends past the end of the mailbox, Chilkat stops at the final message. If start_index is greater than end_index, the method succeeds without appending any messages.

If headers_only is true, Chilkat retrieves the message headers and a partial body. num_body_lines specifies the number of body lines; a value of 0 retrieves the first body line. Attachments are not downloaded. If headers_only is false, Chilkat retrieves the complete messages, including attachments.

If keep_on_server is true, every retrieved message remains on the POP3 server, regardless of ImmediateDelete.

If keep_on_server is false and complete messages are retrieved, Chilkat sends DELE for each message after it is downloaded. If ImmediateDelete = true, Chilkat sends QUIT only after the entire requested set has been downloaded successfully; this commits the deletions and closes the POP3 session. If ImmediateDelete = false, the deletion marks remain pending in the open session until the application calls Pop3EndSession.

If the POP3 connection is lost before QUIT, the session ends and the server forgets all uncommitted deletion marks. Chilkat automatically reconnects and establishes a new session when the next POP3 method is called.

Header-only or partial retrieval never marks messages for deletion, regardless of keep_on_server or ImmediateDelete.

If an error occurs while retrieving multiple messages, processing stops at the first failure. Messages that were successfully retrieved before the failure remain appended to the output EmailBundle; Chilkat does not remove those results or restore the bundle to its prior state.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Retrieves the UIDLs of the messages currently stored in the POP3 mailbox and stores them in uidls. The UIDLs are returned in the server's current mailbox order, with one entry for each message.

A POP3 UIDL, or Unique ID Listing, is a persistent identifier assigned by the mail server. Unlike POP3 message numbers, which can change between sessions, a UIDL remains stable for as long as the message remains in the mailbox.

If no POP3 session is active, Chilkat connects and authenticates automatically. After a successful call, the session remains open for reuse by subsequent POP3 methods.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Retrieves the messages whose UIDLs are listed in uidls and appends them to the EmailBundle in bundle. Existing emails in bundle are preserved, and the retrieved messages remain on the POP3 server.

UIDLs are processed in the order in which they occur in uidls. A duplicate UIDL causes the same message to be appended again. A UIDL that is not present in the mailbox is ignored and does not by itself cause the method to fail.

If headers_only is true, Chilkat retrieves the headers and a partial body. num_body_lines specifies the number of body lines; a value of 0 retrieves the first body line. Attachments are not downloaded. If headers_only is false, Chilkat retrieves the complete messages, including attachments.

If an error occurs while retrieving multiple messages, processing stops at the first failure. Messages that were successfully retrieved before the failure remain appended to the output EmailBundle; Chilkat does not remove those results or restore the bundle to its prior state.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Copies into json any structured JSON details produced by the immediately preceding method call.

Not every MailMan method produces JSON details. Call this method immediately after the operation of interest so the returned information corresponds to that operation.

Returns the number of emails currently available in the POP3 mailbox. Returns -1 if an error occurs.

This method is functionally identical to CheckMail.

Returns an XML document containing information about the messages currently stored in the POP3 mailbox.

The XML includes the UIDL and size, in bytes, for each message in the mailbox. This is useful for scanning mailbox state without downloading the full messages.

Returns Err(chilkat::Error) on failure.

Returns the total combined size, in bytes, of all messages currently stored in the POP3 mailbox. This is also known as the POP3 maildrop size.

If no POP3 session is active, Chilkat connects and authenticates automatically. After a successful call, the session remains open for reuse by subsequent POP3 methods.

Returns -1 on failure.

Gets the digital certificate presented by the SMTP or POP3 server for the current SSL/TLS connection and stores it in cert.

If use_smtp is true, Chilkat returns the certificate for the SMTP connection. If use_smtp is false, Chilkat returns the certificate for the POP3 connection.

This method applies only when the current connection uses SSL/TLS.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Returns the size, in bytes, of the email on the POP3 server identified by uidl. The size includes the full message content, including attachments.

Returns -1 if an error occurs.

Contacts the SMTP server and determines whether it supports the DSN, or Delivery Status Notification, extension defined by RFC 3461.

DSN support is used with properties such as DsnEnvid, DsnNotify, and DsnRet. Returns true if the SMTP server advertises DSN support, otherwise returns false.

Loads emails from a .mbx mailbox file and stores them in bundle.

If a filter has been configured, only the emails matching the filter are returned.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Explicitly opens a connection to the SMTP server and authenticates if a username and password, OAuth2 token, or other applicable authentication settings have been provided.

Calling this method is optional. Email-sending methods such as SendEmail automatically open and authenticate the SMTP connection when needed.

This method is equivalent to calling SmtpConnect followed by SmtpAuthenticate.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Authenticates with the POP3 server using the current POP3 property settings, such as PopUsername, PopPassword, and any authentication-related options.

This method should be called only after a successful call to Pop3Connect. The Pop3BeginSession method performs both steps and is equivalent to calling Pop3Connect followed by Pop3Authenticate.

Calling this method is optional in most applications because POP3 methods that communicate with the server automatically connect and authenticate if no authenticated session is already open.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Explicitly begins a POP3 session by connecting to the POP3 server and authenticating using the current POP3 property settings.

Calling this method is optional. Any method that requires an established POP3 session automatically connects and logs in if a session is not already open.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Explicitly connects to the POP3 server. If SSL/TLS is required by the current property settings, the secure TLS channel is established as part of this call. This method receives the server's initial greeting but does not authenticate.

After Pop3Connect succeeds, call Pop3Authenticate to log in. The Pop3BeginSession method performs both steps and is equivalent to calling Pop3Connect followed by Pop3Authenticate.

Calling this method is optional in most applications because POP3 methods that communicate with the server automatically connect and authenticate if no authenticated session is already open. When finished with the POP3 server, call Pop3EndSession or Pop3EndSessionNoQuit to disconnect.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Sends the POP3 QUIT command and closes the current POP3 connection.

Any messages marked for deletion during the session are permanently deleted when the server accepts QUIT. After the session ends, IsPop3Connected is false and Pop3SessionId returns 0.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Closes the POP3 connection without sending the QUIT command.

Pending deletion marks are not committed. Messages marked with DELE during the session remain in the mailbox after reconnecting.

Use Pop3EndSession when pending deletions should be finalized.

This method should always return true.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Sends a POP3 NOOP command to the server.

This can be useful for keeping a POP3 session alive or for verifying that the current POP3 connection is still open and functioning.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Sends the POP3 RSET command to the server.

Any messages marked for deletion during the current session are unmarked and remain in the mailbox. The POP3 session remains open after a successful reset.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Sends a raw command to the POP3 server and returns the server's response.

If command contains non-US-ASCII characters, charset specifies the character set used to encode the command before it is sent. Examples include utf-8, ansi, iso-8859-1, and Shift_JIS.

This method is intended for advanced use, diagnostics, or issuing POP3 commands not directly exposed by higher-level MailMan methods.

Returns Err(chilkat::Error) on failure.

Sends a simple email to a single recipient without requiring the application to explicitly create an Email object.

The from_addr argument is the sender address, to_addr is the recipient address, subject is the message subject, body is the plain-text body, and smtp_server is the SMTP server hostname.

This method is convenient for simple cases. For attachments, HTML email, CC/BCC recipients, alternate bodies, signing, encryption, or more control over headers and SMTP behavior, create an Email object and use SendEmail instead.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Renders the Email in email as the MIME text that would be sent to the SMTP server, without actually sending the email.

Rendering uses the current MailMan and Email settings and may include MIME formatting, header encoding, replacement-pattern substitution, digital signing, encryption, and other transformations required before transmission.

This method does not modify email. Values generated as part of rendering are produced for the returned MIME and are not written back to the supplied Email. Repeated calls are not guaranteed to produce byte-for-byte identical MIME.

By default, a Bcc header present in email is included in the rendered MIME. Add NoBccHeader to the Email object's UncommonOptions property to omit the Bcc header from the MIME.

Conceptually, SendEmail performs this rendering step and then sends the resulting MIME.

Note: If the MIME may contain 8-bit or binary data, use RenderToMimeBytes or RenderToMimeBd. Returning binary MIME as a string can corrupt bytes that are not valid text.

Returns Err(chilkat::Error) on failure.

Renders the Email in email as MIME bytes and appends the result to rendered_mime.

This method is the BinData version of RenderToMimeBytes. It is useful when the rendered MIME must be preserved as bytes, especially when it may contain 8-bit or binary MIME content.

Rendering does not modify email. Values generated for the rendered MIME are not written back to the supplied Email.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Renders the Email in email as MIME text and appends the result to rendered_mime.

This method is the StringBuilder version of RenderToMime. Rendering does not modify email; values generated for the rendered MIME are not written back to the supplied Email.

Note: If the MIME may contain 8-bit or binary content, use RenderToMimeBytes or RenderToMimeBd instead. Returning binary MIME as text can corrupt data that is not valid text.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Sends each email in bundle. This is equivalent to calling SendEmail once for each email in the bundle.

If an error occurs while sending one email, Chilkat continues attempting to send the remaining emails unless a fatal error occurs that requires the send operation to stop.

Because it can be difficult or impossible to programmatically determine exactly which emails succeeded and which failed after a bundle send, applications that need detailed per-message status should loop through the bundle and call SendEmail for each message individually.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Sends a single email through the configured SMTP server.

Chilkat automatically opens the SMTP connection when needed. After the email is sent, the connection remains open so a subsequent call to SendEmail or another email-sending method can reuse the same SMTP connection. If an SMTP-related property changes, such as SmtpHost, SmtpUsername, password, port, or SSL/TLS settings, Chilkat automatically closes the existing connection and establishes a new one using the updated settings on the next send.

Important: Some SMTP servers do not complete final delivery processing until the SMTP connection is closed. In these cases, call CloseSmtpConnection after sending. Most SMTP servers process the message immediately, so explicitly closing the connection is usually not required.

By default, a Bcc header in email is included in the MIME sent to the SMTP server. To prevent Bcc addresses from appearing in the MIME header, add NoBccHeader to the Email object's UncommonOptions property.

After sending, additional information about the SMTP transaction may be available by calling GetLastJsonData.

If this method fails, examine SmtpFailReason and LastSmtpStatus. The latter is nonzero only when Chilkat established an SMTP session and received a failure status code from the server.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Sends an email from caller-supplied MIME text. The MIME source in mime_source is passed to the SMTP server as the message content.

This method provides complete control over the MIME that is sent. It is useful when the application already has a fully formed MIME message, or when the MIME was created externally and should not be rebuilt from an Email object.

The from_addr argument is the SMTP reverse-path address used in the MAIL FROM command. This is where bounced email and non-delivery reports are normally delivered. It can be different from the From header in the MIME.

recipients is a comma-separated list of plain email addresses used in SMTP RCPT TO commands. Do not include display names or formatted mailbox syntax; supply only addresses such as alice@example.com,bob@example.com.

If this method fails, examine SmtpFailReason and LastSmtpStatus. The latter is nonzero only when Chilkat established an SMTP session and received a failure status code from the server.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Sends an email from caller-supplied MIME bytes contained in mime_data.

This method is the BinData version of SendMimeBytes. It is useful when the MIME must be sent exactly as bytes, such as when it contains binary MIME content, 8bit encodings, or a DKIM/DomainKey signature where byte preservation matters.

from_addr is the SMTP reverse-path address used in the MAIL FROM command. recipients is a comma-separated list of plain email addresses used in SMTP RCPT TO commands. Do not include display names or formatted mailbox syntax in recipients.

If this method fails, examine SmtpFailReason and LastSmtpStatus. The latter is nonzero only when Chilkat established an SMTP session and received a failure status code from the server.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Explicitly specifies the certificate to use when decrypting encrypted email.

The certificate must correspond to the recipient certificate used to encrypt the message, and the associated private key must be available to Chilkat through the certificate itself, an added PFX source, an XML certificate vault, or the platform certificate store where applicable.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Explicitly specifies both the certificate and its associated private key to use when decrypting S/MIME encrypted email.

In most cases, it is simpler to call AddPfxSourceFile or AddPfxSourceData to provide the certificate and private key together in a PFX/PKCS#12 source. On Windows, if the certificate and private key are already installed in the default certificate store, no explicit setup may be needed because MailMan automatically searches the Windows certificate stores.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Sets the POP3 or SMTP password from a SecureString.

The protocol_name argument specifies which password is being set. Use pop3 to set the POP3 password, which is equivalent to setting the PopPassword property. Use smtp to set the SMTP password, which is equivalent to setting the SmtpPassword property.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Sets the client-side certificate to use for SSL/TLS connections.

This is typically not required. Most SSL/TLS connections authenticate the server only, while the client remains unauthenticated at the TLS layer. Use this method only when the SMTP or POP3 server requires TLS client certificate authentication.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Sets the client-side certificate to use for SSL/TLS connections, loading it from PEM data or from a PEM file.

The pem_data_or_filename argument may contain PEM text or the path to a PEM file. The pem_password argument supplies the password if the PEM private key is encrypted.

TLS client certificates are typically required only when the server uses mutual TLS. Most SMTP and POP3 SSL/TLS connections do not require a client certificate.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Sets the client-side certificate to use for SSL/TLS connections, loading it from a PFX/PKCS#12 file.

The pfx_path argument is the path to the PFX file, and pfx_password is the password required to open it.

TLS client certificates are typically required only when the server uses mutual TLS. Most SMTP and POP3 SSL/TLS connections do not require a client certificate.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Authenticates with the SMTP server using the current SMTP property settings, such as SmtpUsername, SmtpPassword, OAuth2 token settings, and other authentication-related options.

This method should be called only after a successful call to SmtpConnect. The OpenSmtpConnection method performs both steps and is equivalent to calling SmtpConnect followed by SmtpAuthenticate.

Calling this method is optional in most applications because SMTP methods that communicate with the server, such as SendEmail, automatically connect and authenticate if no authenticated SMTP connection is already open.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Explicitly connects to the SMTP server. If SSL/TLS is required by the current property settings, the secure TLS channel is established as part of this call. This method receives the server's initial greeting but does not authenticate.

After SmtpConnect succeeds, call SmtpAuthenticate to authenticate. The OpenSmtpConnection method performs both steps and is equivalent to calling SmtpConnect followed by SmtpAuthenticate.

Calling this method is optional in most applications because SMTP methods that communicate with the server, such as SendEmail, automatically connect and authenticate if no authenticated SMTP connection is already open.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Sends an SMTP NOOP command to the server.

This can be useful for testing whether the SMTP connection is working and still valid. If an SMTP connection is not already open, SmtpNoop automatically establishes the connection using the current SMTP property settings.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Sends an SMTP RSET command to the server.

The RSET command resets the server-side state of the current SMTP transaction so the connection can be used to begin a new mail transaction. This method is rarely needed. It would normally only be useful if a mail-sending method failed and left the SMTP connection open in a non-initial state, a situation that should generally not occur with the Chilkat MailMan object.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Sends a raw command to the SMTP server and returns the server's response.

If command contains non-US-ASCII characters, charset specifies the character set used to encode the command before it is sent. Examples include utf-8, ansi, iso-8859-1, and Shift_JIS.

If b_encode_base64 is true, the response is returned in Base64-encoded form. If b_encode_base64 is false, the raw response text is returned.

This method is intended for advanced use, diagnostics, or issuing SMTP commands not directly exposed by higher-level MailMan methods.

Returns Err(chilkat::Error) on failure.

Authenticates with the SSH server using public-key authentication after an SSH tunnel has been opened.

The ssh_login argument is the SSH account name. The priv_key argument is the SshKey containing the private key used for authentication. The matching public key must already be installed for the SSH account on the server.

An SSH tunneling session begins by calling SshOpenTunnel to connect to the SSH server, followed by either SshAuthenticatePk or SshAuthenticatePw to authenticate.

After the SSH tunnel is established and authenticated, MailMan's underlying SMTP or POP3 communication uses the SSH tunnel. No other programming changes are required beyond the initial tunnel setup calls.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Authenticates with the SSH server using an SSH username and password after an SSH tunnel has been opened.

The ssh_login argument is the SSH account name, and ssh_password is the corresponding SSH password.

An SSH tunneling session begins by calling SshOpenTunnel to connect to the SSH server, followed by either SshAuthenticatePw or SshAuthenticatePk to authenticate.

After the SSH tunnel is established and authenticated, MailMan's underlying SMTP or POP3 communication uses the SSH tunnel. No other programming changes are required beyond the initial tunnel setup calls.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Closes the SSH tunnel used for SMTP or POP3 communication.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Connects to an SSH server and opens an SSH tunnel for MailMan's SMTP or POP3 connections.

The ssh_hostname argument is the hostname or IP address of the SSH server. The ssh_port argument is the SSH port, typically 22.

An SSH tunneling session begins by calling SshOpenTunnel, followed by either SshAuthenticatePw or SshAuthenticatePk to authenticate.

After the SSH tunnel is established and authenticated, MailMan's underlying SMTP or POP3 communication uses the SSH tunnel. No other programming changes are required beyond the initial tunnel setup calls.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Provides an XML certificate vault to be searched for certificates and private keys when MailMan performs operations such as encryption, decryption, signing, or signature verification.

Unlike PFX sources added with AddPfxSourceData, AddPfxSourceBd, or AddPfxSourceFile, only one XML certificate vault can be used at a time. If UseCertVault is called more than once, the most recent vault replaces the previously supplied vault.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Configures MailMan to use an existing SSH tunnel provided by the Ssh object in ssh for SMTP and POP3 connections.

This method is similar to UseSshTunnel, except the SSH tunnel is supplied in ssh rather than a Socket object.

Sharing an existing SSH tunnel is useful when multiple objects need to communicate through the same SSH connection. SSH supports multiple logical channels within one tunnel, so SMTP and POP3 connections can exist simultaneously as separate SSH channels.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Configures MailMan to use an existing SSH tunnel provided by a Socket object for SMTP and POP3 connections.

Sharing an existing SSH tunnel is useful when multiple objects need to communicate through the same SSH connection. SSH supports multiple logical channels within one tunnel, so SMTP and POP3 connections can exist simultaneously as separate SSH channels.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Tests whether a TCP/IP connection can be established with the configured POP3 server.

This method verifies connectivity only. It does not prove that POP3 authentication will succeed. Use VerifyPopLogin to test both connection and login.

Returns true if the connection can be established, otherwise returns false.

Tests whether Chilkat can connect to the configured POP3 server and successfully log in using the current POP3 authentication settings.

Use this method to diagnose whether POP3 credentials and authentication settings are correct. If only the TCP/IP connection needs to be tested, use VerifyPopConnection.

Returns true if the connection and login succeed, otherwise returns false.

Begins the SMTP send process for email, sends the recipient addresses to the SMTP server, and then aborts before sending the message content. Recipient addresses rejected by the SMTP server are returned in bad_addrs.

This method can help identify addresses the SMTP server rejects during the SMTP RCPT TO stage. However, it cannot guarantee that all accepted addresses are valid. SMTP servers often accept addresses outside their own domains and only later discover delivery failures when relaying or delivering to the final destination.

Returns Ok(()) for success, Err(chilkat::Error) for failure.

Tests whether a TCP/IP connection can be established with the configured SMTP server.

This method verifies connectivity only. It does not prove that SMTP authentication will succeed. Use VerifySmtpLogin to test both connection and login.

Returns true if the connection can be established, otherwise returns false.

Tests whether Chilkat can connect to the configured SMTP server and successfully authenticate using the current SMTP authentication settings.

Use this method to diagnose whether SMTP credentials and authentication settings are correct. If only the TCP/IP connection needs to be tested, use VerifySmtpConnection.

Returns true if the connection and login succeed, otherwise returns false.

Enables a method call to be aborted by triggering the AbortCheck event at intervals defined by the HeartbeatMs property. If HeartbeatMs is set to its default value of 0, no events will occur. For instance, set HeartbeatMs to 200 to trigger 5 AbortCheck events per second.

Example (closure form; the EventHandler trait method is equivalent):

mail_man.set_heartbeat_ms(250);   // call abort_check 4 times per second

let stop = std::sync::Arc::new(std::sync::atomic::AtomicBool::new(false));
let flag = stop.clone();
mail_man.on_abort_check(move || flag.load(std::sync::atomic::Ordering::Relaxed));
// ... another thread may now abort the method in progress with stop.store(true, Ordering::Relaxed)

This provides the percentage completion for any method involving network communications or time-consuming processing, assuming the progress can be measured as a percentage. This event is triggered only when it's possible and logical to express the operation's progress as a percentage. The pct_done argument will range from 1 to 100. For methods that finish quickly, the number of PercentDone callbacks may vary, but the final callback will have pct_done equal to 100. For longer operations, callbacks will not exceed one per percentage point (e.g., 1, 2, 3, ..., 98, 99, 100).

The PercentDone callback also acts as an AbortCheck event. For fast methods where PercentDone fires, an AbortCheck event may not trigger since the PercentDone callback already provides an opportunity to abort. For longer operations, where time between PercentDone callbacks is extended, AbortCheck callbacks enable more responsive operation termination.

To abort the operation, set the abort output argument to true. This will cause the method to terminate and return a failure status or corresponding failure value.

Example (closure form; the EventHandler trait method is equivalent):

mail_man.on_percent_done(|pct| {
    // pct ranges from 1 to 100.
    println!("Percent done: {pct}");
    false   // return true to abort the method in progress
});

This event callback provides tag name/value pairs that detail what occurs during a method call. To discover existing tag names, create code to handle the event, emit the pairs, and review them. Most tag names are self-explanatory.

Note: Some Chilkat methods don't fire any ProgressInfo events.

Example (closure form; the EventHandler trait method is equivalent):

mail_man.on_progress_info(|name, value| println!("{name}: {value}"));