I have a project that requires emails be sent to external vendors. These emails are required to be encrypted as they contain private information. I have successfully been able to send an encrypted email (using Chilkat). However, I am at a loss as how the recipient (using Outlook) will be able to decrypt said email.
To send an encrypted email, you must use the digital certificate of the recipient. This certificate should contain the receiver’s email address in its Subject. For example, when viewing the intended receiver’s certificate in the Windows Certificate Management Console (certmgr.msc), you should see something like this for the Subject:
E = firstname.lastname@example.org
CN = Chilkat Software, Inc.
O = Chilkat Software, Inc.
L = Wheaton
S = Illinois
C = US
To encrypt, you only need the public key. Your partner may wish to export his/her certificate to a .cer file and then send it to you. There is no danger in making your digital certificate publicly available in a .cer file. (PFX files contain private keys, but .cer files do not.)
To receive an encrypted email in Outlook, a digital ID needs to be imported into Outlook and then associated with the email account. You can do this via the Outlook Options’ Security tab. (It may vary with the version of Outlook. Microsoft is always changing things, so this is not the place to get detailed help on Microsoft Outlook.) In a nutshell, the intended recipient should’ve imported his cert (possibly from a password-protected PFX file) and setup his/her Outlook email account with a digital ID. Once that is done, your email is automatically decrypted by Outlook. If Outlook is not setup correctly, you’ll get a message such as "Can’t open this item. Your Digital ID name can not be found by the underlying security system.".