Here is the log:

Nov 19 13:12:00 Nagios-SLC postfix/qmgr[7540]: 9E4999EE6: from=<root@domain.com>, size=328, nrcpt=2 (queue active)
Nov 19 13:12:00 Nagios-SLC postfix/local[7737]: 9E4999EE6: to=<alert@domain.com>, relay=local, delay=0.04, delays=0.02/0/0/0.02, dsn=5.1.1, status=bounced (unknown user: "alert")
Nov 19 13:12:01 Nagios-SLC postfix/local[7760]: 9E4999EE6: to=<testing@domain.com>, orig_to=<testing>, relay=local, delay=1.3, delays=0.02/0.01/0/1.2, dsn=5.1.1, status=bounced (unknown user: "testing")
Nov 19 13:12:01 Nagios-SLC postfix/cleanup[7735]: DE4D59EE5: message-id=<20091119201201.DE4D59EE5@nagios-slc.domain.com>
Nov 19 13:12:01 Nagios-SLC postfix/qmgr[7540]: DE4D59EE5: from=<>, size=2306, nrcpt=1 (queue active)
Nov 19 13:12:01 Nagios-SLC postfix/bounce[7739]: 9E4999EE6: sender non-delivery notification: DE4D59EE5
Nov 19 13:12:01 Nagios-SLC postfix/qmgr[7540]: 9E4999EE6: removed


This looks like it's trying to send to a user local to the box itself... still not going outside the box.

So looks like a better communication already, although the mail is bounced . So now only remains your user configuration if I'm not mistaking. Does the alert user/mailbox exist on your Exchange server?

Kind regards,

Eric

I GOT IT! Or that is, we got it!

The "relay=local" in that log told me that despite my change to "mydestination" it was still trying to send through a local SMTP instead of using the relay.

So I added the SMTP of exchange back to "relayhost" and it worked. I know that you have it working with the SMTP under Mydestination but for some reason that wasn't flying with me.

So, the series of changes that took place throughout this thread plus this last config change has everything working!

Appreciate your help Eric and your very timely responses!

Fantastic, that's good news. I did miss that one about the local stuff. That shows again that two see more then one. Good job, I'm glad it's working. Thanks for marking the thread as solved.

Kind regards,

Eric