We are having an odd issue with mail being held up the queue viewer on SBS 2011 which happens randomly (Once a day or with a week gap in between) when email is sent externally (Internally we have no issues)
We have an external mail client and we are running Microsoft Exchange 2010. At the same time when mail is sent and received it is filtered by SMX.
We have a smart host setup already that is forwarding to SMX in Exchange / Organization / Hub Tranport / Send Connector. When an email is sent I can easily see it being forwarded to the FQDN address that we were supplied with by SMX in the queue viewer proving that the smart host is correctly forwarding email to SMX and in the SMX administrator console we can see the mail being received and sent out or filtered in other words. When the email is queued it shows up in the queue viewer under the SMX smart host and the FQDN that was used.
I have noticed we do not have a Mail Exchange record setup or anything related to mail on our DNS server could this be the issue? Any help would be much appreciated.