We have an Exchange 2013 box, and we are getting random mail no deliveries to mostly free email isps (gmail, hotmail, yahoo, and aol) where errors are like:
Generating server: OPCSEX.opcs.local
Receiving server: mailin-04.mx.aol.com (64.12.91.196)
XXXXXX@aol.com
8/31/2014 2:56:52 PM - Remote Server at mailin-04.mx.aol.com (64.12.91.196) returned '550 4.4.7 QUEUE.Expired; message expired'
8/31/2014 1:49:53 PM - Remote Server at mailin-04.mx.aol.com (64.12.91.196) returned '451 4.4.0 Primary target IP address responded with: "554 mtaig-mcb02.mx.aol.com ESMTP not accepting connections." Attempted failover to alternate host, but that
did not succeed. Either there are no alternate hosts, or delivery failed to all alternate hosts. The last endpoint attempted was 64.12.91.196:25'
When I research I am reading thinks like the mail record should be a cname, not a record. That dosent make sense to me. Is there a tool that can help me track down the issue, or that verifies that all my DNS records are correct?
Thanks