mail not sending to internal addresses

[deco10]

Hi,
I'm using the mail command and I am able to send mail to my gmail account with out any problems. However when I send mail to deco -at- mycompany.com I nothing happens and no mail ever arrives in my mailbox. It might be worth mentioned that my centos5 is a virtual machine on the same server as the company exchange mail server.

Am I missing something obvious?

From my log file:


Sep 4 13:38:37 centos5 sendmail[19138]: n84HcbSW019138: from=root, size=51, class=0, nrcpts=1, msgid=<200909041738.n84HcbSW019138@centos5.mycompa ny.local>, relay=root@localhost
Sep 4 13:38:37 centos5 sendmail[19139]: n84HcbDP019139: from=<root@centos5.mycompany.local>, size=342, class=0, nrcpts=1, msgid=<200909041738.n84HcbSW019138@centos5.mycompa ny.local>, proto=ESMTP, daemon=MTA, relay=localhost [127.0.0.1] (may be forged)
Sep 4 13:38:37 centos5 sendmail[19138]: n84HcbSW019138: to=myuser@mycompany.ca, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30051, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (n84HcbDP019139 Message accepted for delivery)
Sep 4 13:38:37 centos5 sendmail[19141]: n84HcbDP019139: to=<myuser@mycompany.ca>, ctladdr=<root@centos5.mycompany.local> (0/0), delay=00:00:00, xdelay=00:00:00, mailer=esmtp, pri=120342, relay=mail.mycompany.ca. [179.138.27.23], dsn=2.0.0, stat=Sent ( <200909041738.n84HcbSW019138@centos5.mycompany.loc al> Queued mail for delivery)

[cosmicmittens]

There's a lot of things that could potentially be wrong. It might be easier to debug if you explain your network architecture (by internal do you mean mycompany.com's mail server is behind private nat'd or public switched or what?), but for now let's check the obvious. The logs you post appear to be from the sender's end, do you have logs from the recipient server?

Start from the beginning, let's make sure when can get to the destination:

Make sure the nameservers are pointing to the right place:
$ whois mycompany.com

Now, take those nameservers and check that the MX record is pointing to the right place:
$ dig mycompany.com @<nameserver here> mx

Now, take that mx and make sure that it resolves to the right IP:
$ host <mx goes here>

Now, take the IP address of the mx record and see if you can connect to the smtp server:
$ telnet <IP goes here> 25

If you fail at any step above you have found your bottleneck. If, when you telnet in, you get an smtp banner then your destination is within reach.

If you get a banner then check the receiving server's sendmail logs (assuming you're using sendmail) to see what's up. There are many things that could be wrong: a screwy .procmailrc config, mailboxes need to be rebuilt, virtuserstable messed up, etc.

Report back after trying the above and let us know more info.