Kevin Long:
>
> Hello,
>
> I have a single postfix server servicing my company?s domain and
> several customer domains. All outbound mail is first received by
> postfix, then sent to the same barracuda email service to go on
> to it?s final destination.
>
> I want Postfix to use a specific local IPv4 address when it connects
> to the barracuda relay, depending on which domain the email is
> from. This will ultimately show up in the email headers for the
> recipient, and I need to separate my company from the customers.
Configure an SMTP client in master.cf:
/etc/postfix/master.cf:
barracuda-1.2.3.4 ... . .. .. .. .. smtp
-o smtp_bind_address=1.2.3.4
barracuda-1.2.3.5 ... . .. .. .. .. smtp
-o smtp_bind_address=1.2.3.5
/etc/postfix/main.cf:
sender_dependent_default_transport_maps =
hash:/etc/postfix/sender_transport
/etc/postfix/sender_transport:
example.com barracuda-1.2.3.4:
example.net barracuda-1.2.3.5:
This requires Postfix 2.7 or later.
Not saying that postfix->barracura->internet is a good idea, though.
You could instead do postfix-barracuda-postfix(*) and use the same
trick to set the IP address on the internet-facing Postfix SMTP
client. That is the IP address that remote receivers will use for
their IP-based reputation rankings. They don't care about some IP
address on your internal network behind an outbound relay.
Wietse
