- Outlook clients where showing "Connected to Microsoft Exchange".
- Webmail (owa) was accessible, but sent messages were saved in drafts and no new mail was arriving.
- Microsoft Exchange services were showing running as normal
Tried the following:
- restarted Microsoft Exchange services
- telnet *** produced an error (see below) ***
After a little research on the error and symptoms, here is what I did to fix this problem: Disable Resource Monitoring
-Edit the following file: C:\Program Files\Microsoft\Exchange Server\Bin\EdgeTransport.exe.config (your location might be slightly different)
- Change this line from:
<add key="EnableResourceMonitoring" value="true" />
to:
<add key="EnableResourceMonitoring" value="false" />
- Restart all Microsoft Exchange services
After the above change, mail in queue was sent/received ok.
This was probably happening due to the Back Pressure feature in Exchange Transport service. I am assuming its because this server is way under powered for the services it provides in this environment. I am currently in the process of migrating it over to a new physical server.
