That setting is intended to provide a backup copy. You have a copy on PC, yet also want a backup on server. Your moving the email to another folder is not a signal to delete the backup on server. Thunderbird is doing exactly as designed. The solution is to change your setting for keeping backups on server.

I don't see the word "Backup" anywhere on the setting for this. It's a mail management setting. And the current behaviour is unusable. You end up with messages distributed across possibly hundreds of local folders that are also stored in your "Inbox" on the server. Unmanageable. Changing the setting is not a solution. My clients "Inbox" should reflect what is on the servers "Inbox".

Why else would a person need copies in the server inbox if they also have copy on their PC? It's a backup, that that is the traditional use. If they want what is on server to reflect the true inbox, then they should be using IMAP, not POP, considering the expectations you describe.

Apparently that option used to be called "Until I delete or move them from Inbox". Which explains why this problem didn't occur in the past. Not sure when it changed but the new behaviour is most irritating.

Hello phbcanada

There is this advanced setting

mail.pop3.deleteFromServerOnMove

I did not test it, but maybe it does what you want ?

Wow! Looks good. I found another thread that indicates it works as desired. Thanks for pointing this out. New to me. I'll add to my list of tips.

Thanks gp. I think that's exactly what I need. They must have added that when they changed the default behaviour.