Do I have a DNS problem?
The issue involves two different domains I have, onebigsite.com and racktivity.com. The domain to which the IP address is bound is onebigsite.com. I have a subdomain at the same IP address (mail.onebigsite.com) to handle incoming SMTP mail.
When some users send e-mail to sales@racktivity.com (a legitimate e-mail account on that server) it is delivered just fine without incident.
When some OTHERS (and it seems to be systems that do a reverse DNS lookup first) try to deliver mail to sales@racktivity.com, they actually try to send to mail to sales@onebigsite.com instead. That mailbox doesn't exist and thus the mail gets bounced back.
For example:
I can send mail from a yahoo.com account to sales@racktivity.com and it's delivered without incident. However, sending mail from another server that I have an account on fails to the same address. Here are the headers from the failed e-mail...
The original message was received at Thu, 12 Jun 2003
11:46:54 -0400 (EDT)
from root@localhost
----- The following addresses had permanent fatal errors -----
<sales@racktivity.com>
(reason: 550 Unknown user)
----- Transcript of session follows -----
... while talking to mail.onebigsite.com.:
>>> RCPT To:<sales@onebigsite.com>
<<< 550 Unknown user
550 5.1.1 <sales@racktivity.com>... User unknown
Arrival-Date: Thu, 12 Jun 2003 11:46:54 -0400 (EDT)
Final-Recipient: RFC822; sales@onebigsite.com
Action: failed
Status: 5.1.1
Remote-MTA: DNS; mail.onebigsite.com
Diagnostic-Code: SMTP; 550 Unknown user
Last-Attempt-Date: Thu, 12 Jun 2003 11:46:55 -0400 (EDT)
If you are good with DNS, will you check the records for racktivity.com and onebigsite.com and tell me if I've gone wrong? The MX record for racktivity.com is mail.onebigsite.com. And mail.onebigsite.com is sharing an IP with onebigsite.com.
Thanks in advance!
Steve
