When starting Thunderbird, the status line shows logging in to server but loops; no errors, Thunderbird is 'locked out' waiitng/spinning.

Does that also happen if you start TB in Troubleshoot mode?

A few things to try, even in Troubleshoot mode if you have to. Do one at a time and test:

R. click Inbox > Properties > click 'Repair folder' button, then R. click Inbox > Compact

Clear cache:

- press Ctrl-Shift-Delete

- set 'Time range...' to 'Everything'

- untick all items except 'Cache'

- clear, then restart TB

Clear Startup cache:

- TB menu > Help > Troubleshooting information > click 'Clear startup cache' button on the right

Rename a program file:

- TB menu > Help > Troubleshooting Information

- under the Application Basics section next to Profile Folder, click 'Open Folder'

- close TB

- rename addonStartup.json.lz4 to addonStartup.json.lzx

- restart TB

Change proxy settings:

- TB menu > search for proxy > click 'Settings' button > try the other settings

Ed: Thanks for your reply.

The actual message (and as far as TB gets) is:

<user e-mail: host sending login em> </user>

followed by a small-ish blue spinning circle.

Per your suggestions, TB did come up in Troubleshoot mode (via SHIFT key method), but then went into the discussed state (above message, spinning circle) so I was not able to try anything else.

This (to me) sounds like 'we' need a way to get TB in control, bypassing the login sequence; it would appear Troubleshoot mode does not allow that.

My guess is some file, related to the login process, is corrupted and needs to be re-created/replaced.

Again, the connection to the server is fine (Webmail) works so it's (to me) definitely a TB issue. Also again, I see the normal INBOX page and local folders list, but logging in never completes.

Any further suggestions, or help much appreciated.

Ed: My previous reply was 'edited'; the TB message line is:

user e-mail id: Host contacted; sending login information

There's no way to prevent TB from trying to log in when opening. I agree there might be some corruption, so try a new profile - https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-thunderbird-profiles.

Ed: Wow! More than I EVER wanted to know about profiles and TB internals! What I've done: - used Profile Manager to create a new profile, cleverly called 'Al' - TB has successfully re-started, connected and downloaded ALL the server messages using the 'Al' profile. So far, so good. However, switching back to the original 'default' profile has the same issue - looping trying to log into the server.

So - how do I proceed? luckily, I have a TB profile backup from a week or so ago when TB was logging in as expected. If I wanted to 'reload' that profile, would the 'import' function work while profile Al is being used? Then, presuming that works, would I use Profile Manger to switch to the (old) 'default' profile? What happens to the new messages (from last week or so, when this issue started)? Will they be 'picked up' as NEW from the server?

I read about COPYing information from one profile to another "Recovering information from an old profile" but that was specific to FireFox! Can I (and if so how) selectively copy from an old TB profile to another profile?

I'm confused as to how to proceed; I want the old profile settings, but NOT the login problem, whatever it was AND I want it to JUST pick up server mail from the date the problem started. Any further comments, suggestions or recommendations much appreciated - as is your help until now! Thanks.

Ed: So - how do I proceed? luckily, I have a TB profile backup from a week or so ago when TB was logging in as expected. Close TB > copy the contents of the profile backup folder > paste it into the not-working profile folder > restart TB. If that works, you can just delete the AI profile.