Welcome Pholover; I like it too.
Mail in Avast! is actually pretty straightforward for most systems.
The Mail Shield tab controls the mail setup parameters. On the main page, you select the scanning of incoming and outgoing mail. In the Expert Settings you select pop, imap, smtp and certain other parameters to match your desired configuration. Avast! uses an internal proxy to intercept and scan incoming and outgoing mail. If the mail server is not secure, it simply passes the data back and forth after scanning. If the server uses SSL or TLS, Avast! uses OpenSSL to set up a secure connection to the mail server, and handles the encryption/decryption outside of the client. It is able to scan the incoming/outgoing mail at the point closest to the client where it is not encrypted.
Examples attached are for gmail pop, imap, and smtp setup within Thunderbird. Others are very similar with the obvious changes. The SSL accounts table is generated automatically by Avast! (Mail Shields/Expert Settings/SSL Accounts). It shows the secure connections that have been generated by Avast! if your server is secure. For plaintext email, there is usually no entry.
Some email systems use nonstandard ports, but work pretty much the same way. You may find smtp using port 25 (mostly obsolete) or 465 (Avast! can usually do the translation). I have seen pop3 use 996 also, and if you have your own server you can roll your own with a little effort. To deal with nonstandard ports, you need to go to the Summary page Settings/Troubleshooting/Redirect Settings to direct Avast! to scan these ports. You may also need to edit the SSL Accounts table in some cases.
And there are probably some other email systems that require even a bit more tweaking.
