Hi, on Wednesday I upgraded Thunderbird to Version 31.7.0 on Ubuntu 14.04. After reboot I am not able to delete messages in any of my accounts. I have 12 accounts, two of them are POP accounts, the other are using IMAP. Thunderbird correctly recognizes mails as Junk but I am not able to move them to Trash. Also if I try to send a mail Thunderbird can not move the mail to the Sent folder or to Drafts. If I want to move a mail from one folder to an other, it is not possible too. Sometimes after a fresh restart of Thunderbird I can delete and send mails without problems but after a while the problems occur again. It is very annoying and I don't know why it happens. I even deleted my Trash.msg and corresponding files, then created a new Trash folder in Thunderbird, because I though there would be a problem with that folder. Interestingly it worked for a while and I was able to delete mails, but in the first place this has nothing to do with the problems of moving mails, save them to Drafts or Sent folder. I also copied my whole profile folder from ~/.thunderbird/xxxxxxx.Nicolas to ~/.thunderbird/xxxxxxx.Nicolas2 and added it to profiles.ini, but that was not helping. -safe-mode does also not work, and even deleting the largest of all mailboxes with more that 5 GB of mails did help anything. Before I forget it: I set all "mail.server.serverX.max_cached_connections" to 1 because I found a thread via Google where someone said that would be helpful but it wasn't. I really appreciate your help! Thank you!