Ja uvek uradim 2 bekapa - samo mailove i mailove+sva podešavanja. Pre toga, "kompaktovati" mailbox...
Eh, sad sam kući, a ovde nemam nikakav program za mailove, pa ni TBird. Ako se dobro sećam, desni klik na Inbox i ostale foldere nudi i tu opciju...
Edit: File > Compact Folders
http://kb.mozillazine.org/Thunderbird_:_Tips_:_Compacting_Folders
Follow along with the video below to see how to install our site as a web app on your home screen.
Napomena: this_feature_currently_requires_accessing_site_using_safari