Q: Do you have passwords saved in the Thunderbird Password Manager ? check what is currently saved.

• Menu icon > Settings > Privacy & security
• Under Passwords section
• Click on 'Saved Passwords'
• Click on 'Show Passwords'

Each account will have an incoming and an outgoing smtp line. Pop will say mailbox://account.... Imap will say imap://account.... the outgoing will say smtp://account.... If using oauth then you should not have the individual account lines, just one oauth://account..... line

Check each one has the correct password.

• To edit...right click on line and select 'Edit Password'
• Remove password and type in correct password.
• click on 'Close'

If passwords are not saved then this explains why you get prompted. At time of entering password at prompt make sure you select the checkbox to remember password before clicking on OK.

Q: Do you have any cleanup software installed such as CCleaner or Wisecleaner or even some anti-virus products can offer that sort of facility? If yes, then in that product you need to set up your thunderbird profile name folder as an excluded folder. It is possible the cleanup software is deleting things like session, password and cache files.

No passwords are saved and I know that I will be prompted for one.

Before the last update I could just cancel the "Enter password popup" for the users which I did not want to use at that moment and and that was it. But since the last update I get after cancelling the password, a couple of minutes later, several new popups that I need to enter a password for those accounts.

If the account is set up to check for new mail every eg: 10 minutes then it will ask for password every 10 minutes. Suggest you check 'Account Settings' >'Server Settings' for each account . Uncheck checkbox :' Check for new messages every x minutes.' This means it will check on startup first time and thereafter requires a manual check.

However, if the server supports IDLE and uses PUSH then whenever server gets new mail, it will contact the account to say there is a new mail to download and therefore need password to access server. It's possible there has been a change and server is pushing mail.

Just pressing a cancel would only ever Cancel that particular prompt.