Hi, please help, we have an O365 mail account and in Thunderbird we have POP3 protocol set up, authentication via OAuth, one email address is used on multiple PCs. The account is set up so that messages stay on the server and individual users have the same emails and everyone deletes what they need. The problem is that still, after a while, a window pops up for login, authentication to O365, even if we put the login credentials in memory, this is very annoying and annoying :( Sometimes it also happens that the account completely logs out and no message pops up. O365 are set up as recommended from this site. Thank you all very much for any advice.