All of a sudden, starting today, all emails from my server (Smartermail v12.4) are bouncing back with the following message.
There are over 100 emails in the queue waiting to be sent - some for over 6 hours.
I have about 100 clients who use my service and about 50 of them have called me reporting the same issue. All of their sent mail is bouncing back with the following message.
I restarted Smartermail - did not fix the problem.
I rebooted the whole server - did not fix the problem.
I checked MX Toolbox - none of my IPS are blacklisted.
I checked Smartermail Traffic Summary - nothing appears abnormal - no acct has been compromised.
If it was only 1 or 2 emails, I would not bother - but there are hundreds of users, with accounts using different IPs being affected by this problem.
So, what's going on? Any ideas? (NOTE: It's not just yahoo, gmail or aol, emails sent to everyone outside my server are being delayed.)
The server(s) that the message "re: Yahoo test" is attempting to be sent to has temporarily delayed the delivery for the following recipient(s):
There will be up to 12 more delivery attempt(s) of this message. Do not re-send your message until there are no more delivery attempt(s) and the messages bounces back to you.
I also see 1000 of these errors in the Delivery.log file. Could that be part of the problem?
11:19:00  System.Net.Sockets.SocketException (0x80004005): An attempt was made to access a socket in a way forbidden by its access permissions 184.108.40.206:25