Hello there

If the symptoms is there that you can t delete messages it may be caused by a corrupted trash folder .

Try to create a solution and delete that trash folder completely .

Open the profile folder. Go to the 3 striped block. Search for the help function>Trouble shoot information ,that tab wil open. Under the application basics section click on show in finder .

The profile folder is there after that. Close Thunderbird.

Open and go to file manager and open the mail folder.(or IMAPmail or if you using pop with that affected account) Open and go to the folder with your incoming mail server name.(something like imap or pop .googlemail.com)

Select there the trash.msf file and delete them. Sometimes it been called bin or deleted. So look good for what you delete .

IMAP Restart Thunderbird if that is possible . By IMAP account thee will be automaticly a new trash can .

Pop In the folder list , right click on your account name and select >new folder.

Enter Trash as folder s name and confirm by clicking on > create folder.

I'm shure that there is created the new trashcan .

Greetings Firefox fox volunteer.

Hello there

If the story is something else Let me hear from you again .

Greetings Firefox volunteer

Try to rebuild the index file of the troubled folder.

Right-click the folder - Properties - Repair Folder