I have unwittingly been using Tbird for years with the option "keep messages for this account on this computer" checked since I guess that's the default setting. I want to get rid of the offline storage of emails to make my Tbird profile as small as possible for fast backup copying of Tbird's profile. My three email accounts are IMAP gmail accounts. 1. If I uncheck "keep messages for this account on this computer", I should not lose any emails and everything should continue working exactly as it always has, is that right? (I don't do emails in offline mode) 2. Then I guess I need to do FILE > COMPACT FOLDERS to get rid of all emails stored on my PC is that right? Thanks for any help, Skyzoomer