why did everything suddenly go into trash?
Yesterday after I sent a message I checked my "sent" folder and saw that there was nothing there. Checking inbox showed only a dozen messages from years ago, where previously there were over a thousand (many unread). Even worse all my subfolders, where I organize all the messages I want to keep, were empty! I now have no record of anything I received or sent, and I rely on those being there. Is this somehow simply a screen of some kind which is showing me only certain messages or have I really lost everything? Even the "all mail" folder shows nothing. This is an imap account.
ప్రత్యుత్తరాలన్నీ (1)
Is this somehow simply a screen of some kind which is showing me only certain messages or have I really lost everything?
It's quite common that anti-virus software is messing with Thunderbird mail files and hence causing corruption. As a result it's quite possible that data is lost. See http://kb.mozillazine.org/Disappearing_mail
It is therefore recommended to create an exception for the Thunderbird profile folder, so that the anti-virus real-time scanner won't attempt to scan the profile with your mail.
For more information on the profile location see http://kb.mozillazine.org/Profile_folder_-_Thunderbird
Also see http://kb.mozillazine.org/Keep_it_working_-_Thunderbird
You can restore lost data from a backup of your Thunderbird profile, assuming you did create one in the first place. https://support.mozilla.org/en-US/kb/profiles-tb#w_backing-up-a-profile
Also try to login to your account via webmail and check what's left on the server.