Hi This list of diagnosis steps is specifically for High CPU Usage by Thunderbird Portable version 3, on Windows XP, posted in 2010. Not really relevant to Thunderbird ver 60 on Windows 10. Would you like to rephrase your question? Agnes

My bad - this list is repeated on various Wiki sources, some of which are long out of date. However it still was written for memory usage problems and the most recent version I can find has only recently ceased referring to XP. What is your actual problem and what are the symptoms? Agnes

ldesaul said

Seriously? ... Diagnosis Steps ... long list from https://wiki.mozilla.org/Thunderbird:Testing:Memory_Usage_Problems

So at least do numbers 1-5 in https://wiki.mozilla.org/Thunderbird:Testing:Memory_Usage_Problems#Diagnosis_Steps - that effectively checks 50% of the possible causes.

AgnesRM said

Hi This list of diagnosis steps is specifically for High CPU Usage by Thunderbird Portable version 3, on Windows XP, posted in 2010. Not really relevant to Thunderbird ver 60 on Windows 10. Would you like to rephrase your question? Agnes

The items in https://wiki.mozilla.org/Thunderbird:Testing:Memory_Usage_Problems#Diagnosis_Steps that refer to XP are not specific to XP.

Thanks, I am trying eM. No time to mess with this.