Postfix/SMTP authentication process
 

Can someone explain to me how the authentication process works in Postfix when a mail client connects.

I really want to know about password authentication not being passed in the clear. I am fuzzy on the use of TLS etc, the interaction with an IMAP server like Cyrus and the password verifaction process.

I suppose I am after a clear model not just adding lines into the config files to make it work.

Regards

Passwords are passed in clear text, which is why you can add tls over the top to encrypt that traffic. Not really sure what else to say.

Have you read the tls howtos on www.postfix.org?

Note that IMAP sertvers are different, but they should be able to use the same certificate if you want. I don't know cyrus-imap well, but you can get postfix to use dovecot's authentication instead if you want. have a look at http://www.postfix.org/SASL_README.html#server_dovecot