[Mailman-Users] Qmail and Mailman and relaying and source addresses

[cls at pk.greens.org]

My Qmail listens to port 25 though the usual tcpserver + rblsmtpd caravan.
We use ORDB and SPEWS and SBL and it stops most of the junk.  I allow
relaying for my other two servers and localhost.

When I telnet to port 25 on this host, qmail-smtpd records a connect
from 127.0.0.1, the local interface.

I discovered by trial and error that, when it wants to send, Mailman
somehow comes in through the external interface.  qmail-smtpd sees
that IP number.

Qmail-smtpd quite properly refuses to relay.  It says something polite
like "Sorry, you're not in my list of rcpthosts."  Mailman fails to record
this helpful message anywhere I could find.  It just counts a mysterious
"bounce."  This is a bug in Mailman.  A mailing list program needs to
preserve *somewhere* the error messages from the MTAs on which it relies.

The solution is to add
w.x.y.z:allow,RELAYCLIENT=""
to tcprules.txt, where w.x.y.z is your external IP address, and
rebuild tcprules.cdb.


Cameron