Hello, I'm finding a way to have a pool of smtp-auth servers in front of my actuals servers to permit relay to our customers. Now users sends emails connecting to the right IP via mail.domain.tld, with authentication. Every server has it's own user database in mysql.
I'd like to have a pool of server (with round robin, ideally with postfix + sasl + dovecot) that authenticate the users with the actuals servers and then pointing mail.domain.tld to this pool and not to one server.
My trouble is how to authenticate users.
Can I use:
http://wiki.dovecot.org/Authentication/MultipleDatabases
to tell Dovecot to authenticate with every MySQL database on the servers "behind"?
If yes, is there a better way to do this considering I'm already using some proxy machines (dovecot) for pop3/imap and so I already have a db with domain.tld -> IP of the server? I also have some machine without a MySQL DB for users (vpopmail + cdb), so the option with MultipleDatabases will be good only for some machines.
Something similar to the proxy mechanism that I already use for pop3/imsp will be good: the proxy connect to the machine behind that do the authentication, I only need a table with domain -> server IP (that I already have).
Thanks for any advice.