Soldato
- Joined
- 20 Oct 2008
- Posts
- 12,082
I’m running Exchange 2007 as a part of SBS 2008. I recently changed ISPs and as a result my static IP changed, I updated my MX record and assumed that would be that.
I then found out that a company I have dealings with could no longer send emails to my domain. This company is also running Exchange 2007 on SBS 2008.
As far as I can tell there are no other problems either sending or receiving for either domain.
According to mxtoolbox.com everything on my domain is working as it should. I’ve also checked with Microsoft’s Remote Connectivity Analyzer and received a clean bill of health.
I’ve got remote access to the other companies server so I did some checking at their end.
From their server I tried nslookup –q=mx for my domain and it returned the correct information. I was also able to successfully send myself an email using telnet.
Using the Exchange Queue Viewer on their server I found that the messages they’d tried to send to me were flagged as 451 4.4.0 DNS query failed. After a bit of searching I followed a suggestion to enable ‘Use the External DNS Lookup settings on the transport server’ and this does seem to have fixed things.
Does anyone have any insight as to what the underlying problem might be?
I then found out that a company I have dealings with could no longer send emails to my domain. This company is also running Exchange 2007 on SBS 2008.
As far as I can tell there are no other problems either sending or receiving for either domain.
According to mxtoolbox.com everything on my domain is working as it should. I’ve also checked with Microsoft’s Remote Connectivity Analyzer and received a clean bill of health.
I’ve got remote access to the other companies server so I did some checking at their end.
From their server I tried nslookup –q=mx for my domain and it returned the correct information. I was also able to successfully send myself an email using telnet.
Using the Exchange Queue Viewer on their server I found that the messages they’d tried to send to me were flagged as 451 4.4.0 DNS query failed. After a bit of searching I followed a suggestion to enable ‘Use the External DNS Lookup settings on the transport server’ and this does seem to have fixed things.
Does anyone have any insight as to what the underlying problem might be?