sendmail relay or DNS problem?

[eddieedwards]

I have an issue here that might be due to sendmail on my Scalix box. Until recently, all incoming mail came through our firewall, to a Barracuda Spam Filter, then to our legacy mail server (running Suse SLOX) where mail was forwarded on to Scalix. Once I had all the PDLs migrated over, I redirected traffic from the 'Cuda straight to Scalix. Then yesterday, I turned off the SMTP (Postfix) service on the SLOX box and mail started to pile up in the sendmail queue, complaining that connections to mydomain.com were refused. After reading the logs and running sendmail -q -v to flush the queue, it looks like sendmail on Scalix is trying to route the mail to the old email server. What gives? DNS MX record is the Scalix box.

eddie

[eddieedwards]

OK, I think I figured out the problem, but am not sure how to fix it. What I think is happening is that if a message comes in destined for an address that is not in Scalix ( like nobody@mydomain.com), sendmail decides to relay it on to the mydomain.com host. It must be a smarthost/relay issue in sendmail, but I'm not 100% sure. Ideally, Scalix would not accept mail at all for unkown users and refuse it.

[konman]

eddieedwards,

I think that I have the same problem as you - I think that sendmail is sending scalix spam and it seems to just sit in sendmail and clogs up the spool directory.

Were you able to tell sendmail to give up on sending mail to scalix which scalix refused?

Regards,
KonMan.

[eddieedwards]

IIRC, our domain name without a host in front of it, was still resolving to the old SLOX box. So, if mail for someone@mydomain.com came in and Scalix didn't have a record of "someone" it would try to sending it on to whomever resolved the domain portion of the address (mydomain.com). I fixed it by explicitly telling DNS that mydomain.com resolved to the Scalix box.