Sendmail on a multihomed server...

[Steven W. Orr]

On Wednesday, Jun 30th 2004 at 14:41 -0400, quoth Tom Buskey:

=>
=>> That's not quite it. The problem is that when sendmail on the server
=>> makes a connection to AOL's server, it does so from an IP address that
=>> AOL thinks is an open relay, and rejects delivery of the mail. I have
=>> fixed the apparent open relay problem, but AOL still has that IP address
=>> blacklisted. There are other IP addresses assigned to that server, but
=>> Sendmail still prefers the primary one assigned to eth0. The others are
=>> assigned to eth0:1, eth0:2, etc.
=>>
=>> It is becoming apparent that Sendmail does not have a way to bind an
=>> outgoing connection to a particular IP address, but relies on the kernel
=>> to make that decision through the routing tables. So, comma, I am going
=>> to have to modify the routing tables on that server, it seems -- but
=>> since that server is remote and is a money maker, I am loathe to do
=>> anything to the routing tables at all. Another approach is to juggle the
=>> IP address assignments on the NICs, but I am loathe to do that as well
=>> for the same reasons.
=>
=>I'm in AOL's list becausemy server is in comcast's dynamic IP space. 
=>Similar issue.
=>
=>I'm running sendmail on RH9.  Here's my solution:
=>
=>cd /etc/mail
=>cat >mailertable <<EOF
=>aol.com esmtp:smtp.comcast.net
=>netscape.net esmtp:smtp.comcast.net
=>earthlink.net esmtp:smtp.comcast.net
=>rcn.net esmtp:smtp.comcast.net
=>rcn.com esmtp:smtp.comcast.net
=>prodigy.net esmtp:smtp.comcast.net
=>sbcglobal.net esmtp:smtp.comcast.net
=>bbn.com esmtp:smtp.comcast.net
=>monster.com esmtp:smtp.comcast.net
=>zoneedit.com esmtp:smtp.comcast.net
=>EOF
=>
=>make mailertable.db
=>/etc/init.d/sendmail restart
=>
=>Now, anytime I try to email @aol.com, it gets relayed through comcast's
=>official server which AOL allows.  Anything not on the list gets sent
=>direct from my server.
=>
=>I suspect you don't need to deal with IPs and routing, etc......
=>
=>AOL doesn't listen to complaints much.  I had an intermittant issue
=>sending to an @aol.com account w/ one of my users a few years back.  It
=>turns out, from my end, AOL had a misconfigured server, 1 of 8.  If the
=>email went through that one, it bounced.  The other 7 were fine.  AOL
=>never acknowledged the problem.

That's sort of what I was suggesting but you're doing it for one domain at 
a time. If it's just AOL that's complaining then your solution should be 
useable.

One thing you should be aware of: Whenever you rebuild a db file (e.g., 
alias, mailertable, access, etc...) there is never a need to restart 
sendmail. Access of any db file is always done fresh. The only time that 
sendmail needs to be restarted is if text files need to be reread from 
initialization (e.g., sendmail.mc, local-host-names, trusted-users, 
etc...)

-- 
Time flies like the wind. Fruit flies like a banana. Stranger things have  .0.
happened but none stranger than this. Does your driver's license say Organ ..0
Donor?Black holes are where God divided by zero. Listen to me! We are all- 000
individuals! What if this weren't a hypothetical question?
steveo at syslang.net