Many thanks to all of you who have provided guidance in trying to resolve this CPU/RAM consumption issue so far, but sadly it still persists.
I have installed the latest version of Thunderbird and the issue is exactly the same. :o ::slight_smile:

No other other programs on my machine, except these email clients, trigger or upset Avast in this manner.
Strange, that in all the 12 years that I have been using Avast both free and paid versions, this is the only paid version that has issues. :cry: :frowning:

My next plan of action, if none of you suggest otherwise, is to completely un-install, remove all traces of Alwil/Avast from the registry, reboot several times and then install the latest FREE version of Avast.

If the problem disappears, I will kiss the money I paid for Avast Internet Security as a bad bet and stick with the free version.

.