postfix question

[n j]

Hello,

does anybody know is it possible with Postfix to "route" e-mail based
on either the inet interface message came from or the sender of a
message? I'm using Postfix v.2.3.8 on a multihomed machine and have
two smtpd's defined in master.cf. What I would like is that mail
submitted through smtpd that is listening on A.B.C.D goes out through
the smtp client that binds to A.B.C.D and the rest of the mail go
through the other smtp client. The problem as I see it is that, once
messages arrive in the queue, it becomes irrelevant where they came
from and the only "routing" that is available is recipient-based.

Thanks for any suggestions!

-- 
Nino