re: C:\Users\****\AppData\Roaming\Thunderbird\Profiles\11znkop2.default\Mail

There should not be any *.tmp file in the 'Mail' folder.

'Mail' folder should only contain :

• 'Local Folders' folder
• Pop 'mail account name' folders
• 'smart mailboxes' folder

This makes me think that some other program may have done this and the first obvious thing to check is Anti-Virus. What Anti-Virus product are you using ? eg: Avast

Do you allow scanning of Thunderbird files and folders on startup? Do you allow scanning of incoming and outgoing mail? Have you got any auto scans which include Thunderbird folders?

Toad-Hall said

re: C:\Users\****\AppData\Roaming\Thunderbird\Profiles\11znkop2.default\Mail There should not be any *.tmp file in the 'Mail' folder. 'Mail' folder should only contain :

• 'Local Folders' folder
• Pop 'mail account name' folders
• 'smart mailboxes' folder

This makes me think that some other program may have done this and the first obvious thing to check is Anti-Virus. What Anti-Virus product are you using ? eg: Avast Do you allow scanning of Thunderbird files and folders on startup? Do you allow scanning of incoming and outgoing mail? Have you got any auto scans which include Thunderbird folders?

Currently the PC is using windows defender, I have not made any changes to it, but i have other pc's set up the same way with no issues

As those files were created by something as yet unknown. Suggest you first scan computer.

Start computer in 'Safe Mode' - Not 'Save mode with Networking' Run scans.

Do you use anything like 'CCLeaner' ?

re :I have several .tmp files Can you confirm that they really are .tmp and not .nstmp as nstmp is due to compacting being interupted.

I agree with Toad-Hall, something might be interfering.

On the other hand you might be seeing https://bugzilla.mozilla.org/show_bug.cgi?id=1403771 which is fixed in version 60.

Reporter, does your problem go away if you install and run 60 from https://www.thunderbird.net/en-US/channel/  ??