Hey, I have the exact same problem on different computers, so I guess it has something to do with my specific mail account settings. The problem is that thunderbirds tends to freeze for several minutes. This happens at least five times a day. Most of the time this occurs when I try to archive a mail but it also happens when I recieve a mail while thunderbird is in the background (the popup freezes halfway through appearing) or when open the "Write Message" window. I have two computers running thunderbird. Both use Windows 10 64bit. One runs Thunderbird 38.7 while the other runs Earlybird 47.0a2. Both have the calendar add-on disabled and use no other add-ons. Both should be using the same configuration of mail accounts: I have 4 Gmail accounts. One of them is a Google Apps for Work account. For another I added a different (not gmail) smtp server as default sending address. I use the gmail archive mail system a lot. Each of the accounts has only a few mails in the inbox and a few thousand in the archive. Thank you very much for all the help you can give.