I am a new member to this forum. I am also a new Network Admin and I inherited Exchange 2003.
I have had several clients who are unable to send emails to my firm. It only appears to be a few users from different domains (gmail.com, embarqmail.com, mckenzietank.com) These are the only domains that I'm aware of at the present time. The issue appears to happen with or without attachments.
Example 1 error message: "A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed: *****@mydomain.com (while not connected): 554 5.4.7 [internal] exceeded max time without delivery.
Example 2 error message:
"This is a warning message only. You do not need to resend your message. Delivery to the following recipient has been delayed: *****@mydomain.com Message will be retried for 2 more day (s) Technical details of temporary failure: Connection was dropped by remote host (Sent_Mail).
The only changes I've made was to the Default SMTP Virtual Server>Relay Restrictions from "Only the list below" to "All except the list below".
Could it be some sort of DNS or MX record issue? I know there haven't been any changes made. Just a thought.
Any help concerning this issue will be greatly appreciated.