Summary
When there are many outbound email messages, the IMSS server experiences high CPU usage problems and there are a lot of connections coming from 127.0.0.1 seen on the real-time monitor.
In addition, IMSSChild.exe has multiple copies that trigger high CPU utilization on the machine hosting IMSS.
Details
When this happens, check the following:
- Scanning Exceptions Policy
- Actions against malformed messages
Checking these two areas will help determine the cause of the issue. There are instances when malformed messages are looping inside the IMSS server because of inappropriate action defined under Scanning Exceptions Policy, and therefore triggering high CPU problems.
To resolve the issue:
- Make sure that the action for Malformed Messages in the Scanning Exceptions Policy is Delete Entire Message instead of Log Only.
- Check the Message Tracking Log. No messages sent to xxx@xxx.com should appear.
- If messages are still received, do the following:
- Log in to the IMSS server console.
- Go to Administration > SMTP Routing > Connections > Connection Control.
- Under Accept all, except the following list, add 127.0.0.1.
- Observe the IMSS Monitor for a few minutes and check if the mail messages are received from xxx@xxx.com.
- Check the Message Tracking Log and see if there are mail messages received from xxx@xxx.com.
- Go back to the IMSS server console and under Accept all, except the following list, remove 127.0.0.1.
- Observe the IMSS Monitor for a few minutes. This time, no mail message should be received from xxx@xxx.com.
- Check the Message Tracking Log. No other mail messages should be received from xxx@xxx.com.
