can’t send email to certain domain
I have 2 domains
one NT4 & Exchange 5.5
one W2k3 & Exchange 2k3
I can send and receive messages to users at a company called 'area-adubon.com' when logged in and using the Exchange 2003 server as mail agent.
I can only recieve from 'area-audubon.com' when logged on and using Exchange 5.5 server.
I get a NDR report with the following:
Your message did not reach some or all of the intended recipients.
Subject: 5.5 test
Sent: 8/10/2005 1:51 PM
The following recipient(s) could not be reached:
User on 8/10/2005 1:51 PM
Unable to deliver the message due to a communications failure
I was thinking that maybe they had the domain that the 5.5 server is on blocked or something.
It started about a week ago. Before that all was well.
I have made no changes to that domain or server.
any ideas?
Software/Hardware used:
Software/Hardware used:
ASKED:
August 10, 2005 3:10 PM
UPDATED:
August 11, 2005 12:56 PM
RELATED QUESTIONS
- The following recipient(s) could not be reached
- 5.1.1 e-mail account does not exist at the organization
- Error message: You do not have permission to send to this recipient"
- None of the authentication methods supported by this client are supported by your server.
- How to find hidden recipients, contacts and Exchange Distribution Groups in Active Directory
Answer Wiki:
Insure that a reverse lookup can be done on the 5.5 mailservers IP and DNS Name. Alot of mailservers are set to reject email that come form email servers with out a reverse lookup or PTR Record associated with it.
To see all answers submitted to the Answer Wiki: View Answer History.
Which server is acting as the smart host?
Is the communications totally internal or internal to external?
Do you use a gateway service in a DMZ that acts as a relay?
Has anyone changed this gateway? Any network changes (ACL, NAT, etc.)?
these two domains do not trust each other, nor do the exchange organizations have any thing to do with one another.
they are completely separate other than the subnet.
There have been no configuration changes at any level.
Is is possible that exchange 5.5 doesn’t recognize a domain with a hypen in the name? (area-audobon.com)?