Ok I got a weird problem:

Qmail's outgoing IP address it's the one from eth0:1 instead of eth0 after we added 3 extra IP addresses.

I modified the entries in /etc/xinetd.d/smtp_psa and added bind to eth0 IP, it binds successfully but upon communicating to other SMTP addresses it's still going nanners and connects from the eth0:1 IP.

Any ideeas?

I guess qmail outgoing IP patch it's out of the question on Plesk right?

Please don't confuse binded address with the outgoing address.