EUREKA !!!

Friends, I think I may have found the cause of AvastSvc.exe creating very high CPU and Memory usage.

I went to the following in the Avast User Interface :- Settings → Active Protection → Mail Shield → Mail Shield Settings → SSL scanning.

□ Scan SSL connections

Here I unchecked the box.

Now, when either email client is executed, the CPU/RAM activity momentarily rises to 50% and returns to around the acceptable 8-10%, regardless of how long I keep the email client running.

Looks like this this may be the culprit after all. Will report back here tomorrow to confirm if this is the case. :wink: