Feature request: relaying to different smarthosts

[leahneukirchen]

As a notqmail user, I want to relay mail via different smarthosts according to the Sender or From address, e.g. to send work mail through the work SMTP server and private mail over a different host.

Together with #174, this also needs to support different credentials per smarthost.

[schmonz]

IIRC, you've mentioned s/qmail has this functionality. How does one configure it? Any shortcomings of that approach, or would we do well to borrow it?

[leahneukirchen]

It adds a new config file to qmail-remote:

       authsenders
            Authenticated sender.  For each sender included in authsenders:
            sender:relay;port|user|password qmail-remote will try SMTP
            Authentication of type CRAM-MD5, LOGIN, or PLAIN with the provided
            user name user and password password (the authentication
            information) and eventually relay the mail through relay on port
            port.  The use of relay and port follows the same rules as for
            smtproutes Note: In case sender is empty, qmail-remote will try to
            deliver each outgoing mail SMTP authenticated. If the
            authentication information is missing, the mail is delivered none-
            authenticated.  authsenders can be constructed as follows:

               @example.com:relay.example.com|user|passwd
               info@example.com:relay.example.com;26|infouser|infopasswd
               :mailrelay.example.com|e=mc2|testpass

[schmonz]

Cool, we may as well be compatible with that.