Can your .NET email control verify that an email address exists? I think it is done by connecting to the server and starting the communication. I understand this method doesn’t guarantee delivery, but it at least can verify when email are not correct.
Yes, but it’s not possible to be 100% correct and much depends on your SMTP server. Chilkat’s email component provides a few features to help verify email addresses:
- VerifyRecipients — This is a new Mailman method that is like SendEmail, but it stops short of actually sending the email. It is used to initiate the SMTP protocol process with the SMTP server for the purpose of seeing which email addresses are rejected by the server. More details are available here.
- MxLookup — This method can do a DNS MX lookup on an email address to determine if an MX record exists for the mail server. It does not guarantee that the specific account exists at that server.
- BounceAddress — When sending email, set the BounceAddress property equal to an email address where you want DSN notifications to be delivered. You can the write a program to read this mailbox and process DSN failures to clean your list (if you are managing a list).