What are your settings for sent mail? Since gmail automatically copies sent messages, 'Place a copy in' in the Copies & Folders section of Account Settings should be unchecked. Sent messages are stored in Sent Mail, which you can view by right-clicking the account in the Folder Pane, Subscribe, Refresh, and checking the box for Sent Mail.

If you didn't have the accounts set up this way, does doing so eliminate the errors?

thanks sfhowes

yes this change does stop the error message and yes gmail copy is fine.

BUT this has no impact on the problem of copying from a folder in one account to a folder in another account. per the second part of my problem.

Also this setting has not changed since I started using Thunderbird years ago, so something in the 91 upgrade has changed the behavior somewhere ?

thanks

Robin

How many messages are you trying to copy between accounts? It probably isn't going to work with several messages, and it probably works better if you use Local Folders as an intermediate location instead of copying between IMAP folders directly.

I don't have much experience copying between IMAP folders, but IMAP management is often adjusted, for better or worse, in almost every TB release.

thanks again for quick reply

I have only ever copied one message at a time, just to be safe  :-)

Using a local folder as an intermediary does NOT work unfortunately. The email goes into the Local folder okay but I cannot move it to any of my gmail account folders at all, not even the one it came from ?

This is the first time the moving between folders in my different accounts has ever failed in over a decade.

Can this be investigated further please.

cheers

Robin

You can submit it to Bugzilla, but I advise you to state specific 'steps to reproduce' and see if the issue exists in a new profile. I find it odd that you can't even move a single message from Local Folders to an IMAP folder, as this is a common operation.

thanks again

I will save my data and reinstall Thunderbird from scratch to see if that fixes the problem. Which I have not done for a decade  :-(

Robin

I am having similar problem with sent folder on multiple imap accounts on aplus.net hosted emails I can subscribe close and reopen and sometimes it sticks, other times I find out when it cant copy, usually a very important email, to the sent folder.