Yet another bug of the type: "That domain isn't in my list of allowed rcpthosts"
Posted on 2006-11-21
Our client has an Exchange 2000 Server.
Recently - and this is probably due to more strictness from server admins around the world - a lot of their mails have started bouncing back with various error messages.
So I started fixing them one by one. A recent one was caused by no Reverse DNS on the mail server. I asked our ISP to create one and it seems to have fixed some bouncebacks. Today we got this message:
The following recipient(s) could not be reached:
'Thomas (email@example.com)' on 11/21/2006 7:46 PM
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<stable-mail.stable.com #5.5.0 smtp;553 sorry, that domain isn't in my list of allowed rcpthosts (#5.5.3 - chkuser)>
As you can see, our Exchange server advertises itself as "stable-mail.stable.com".
Unfortunately, that is an internal name. This client does not own stable.com, and stable-mail.stable.com is non-existent and impossible to ping from the internet.
It's just a fake internal name.
Here's the full header when this client sends me an email. User email replaced by firstname.lastname@example.org, and myself replaced by email@example.com.
IP's have also been changed. If you message me directly, I'll send you the full log:
Received: (qmail 16369 invoked by uid 90); 22 Nov 2006 00:47:03 -0000
Received: from firstname.lastname@example.org by tektonik by uid 71 with qmail-scanner-1.22
(f-prot: 3.12/. spamassassin: 2.63. Clear:RC:0(18.104.22.168):SA:0(-4.6/6.0):.
Processed in 6.110263 secs); 22 Nov 2006 00:47:03 -0000
Received: from 22.214.171.124 by smg with SMTP; 22 Nov 2006 00:46:57 -0000
Received: from stable-mail.stable.com (126.96.36.199)
by 0 with SMTP; 22 Nov 2006 00:46:53 -0000
Subject: FW: email problem
X-MimeOLE: Produced By Microsoft Exchange V6.0.6603.0
Date: Tue, 21 Nov 2006 19:46:51 -0500
Thread-Topic: email problem
My question is:
- why aren't we allowed tu use internal names like mail-stable.stable.com?
- there is a reverse DNS entry for the real IP address of that server, so why isn't the destination server using that instead of the stupid internal name we advertise?
- do you see any solution?