Email has been running in background for a long time and I need to shut it down and restart empty.
With hundreds of thousands of emails and 30+ files the program is updating each and taking days. This eats a lot of resources. Is it possible to close and delete the entire program and start fresh?
Wšykne wótegrona (1)
Look at https://support.mozilla.org/en-US/kb/using-multiple-profiles and create a new profile; DON'T delete your old one yet. The new profile will be 'empty', so you will need to re-enter your email accounts.
As an additional or alternate step, you can store your old emails in a separate directory or media and then delete them from your active TB folders. See http://barryduggan.info/exportMail.php