Issues with Exchange 2010 smtp smart host
This evening my Exchange 2010 server started queuing external mail on queue viewer, it is connected to a Smarthost (smtp.managedapps.co.uk) for external emails
all internal mail and external email coming in are ok.
So I restarted the Transport service, same issue.
Sadly My ISP has closed since I found the issue out later in the evening
I tried telnetting smtp.managedapps.co.uk on port 25 and get no connection
Disturbingly when I went to the www.managedapps.co.uk website it was down
Waited a while and it looks like website is backup again and I could telnet the smarthost.
Although restarting the transport service again to try, all external emails are still stuck in outgoing queue with this error:
451 4.4.0 primary target ip address responded with 421 4.4.2 connection dropped due to socket error
Is this still ISP end issue or is there anything I could do ?
Thanks as always