Tom Collins wrote:
Even if it's possible to set up imap-before-smtp, you'll be much better
off if you have your clients use SMTP AUTH instead. More reliable, more
predictable, and supported by almost every email client out there.
If you really want to try it, consider Dovecot instead of Courier. I
think dovecot uses vchkpw, and is probably going to be easier to configure.
dovecot for smtp-auth. dovecot has vpopmail bindings AND sasl support.
You won't need courier-auth or courier-imap anymore. postfix has support
for dovecot-sasl. If you are using something else...I have not tried them.