Passwords can only be created and modified in the webmail account accessed via a browser. Once this is done then you can update the saved passwords in Thunderbird.

Menu icon > Preferences / Settings > Privacy & security Under Passwords section click on 'Saved Passwords' click omn 'Show Paswords' You should have two lines for each mail account.

If pop...mailbox://account....and smtp://..... If imap....imap://account...and smtp://...

Right click on each line and select 'Edit Password' Complete clear allt he content Make sure the 'Caps Lock ' on keyboard is not switched on Carefull type the correct password

When finished click on 'Close' Exit Thunderbird and wait a few moments for background processes to complete. Start Thunderbird.

The login may have failed for a number of reasons.

Firewall may be blocking Thunderbirds access to the internet. Sometimes an update in Thunderbird will confuse a Firewall as it thinks it's a different program.

Exit Thunderbird Access Firewall Thunderbird must be set up as an allowed program. If already set up as allowed - then block it, ok it. Access Firewall again and reset Thunderbird as an allowed program.

Temporary loss of internet - bad internet connection.

Server Settings not correct - such as... Authentication Method - Normal Password - this option not selected Connection Security: eg: SSL/TLS not set up when server expects it Using wrong port. Password needs updating