Four folders in “Local Folders\Trash“ cannot be permanently deleted. They can be deleted but, after exiting and restarting Thunderbird, they appear in “Folders\Trash“ again. These folders have 8-character suffixes added by Thunderbird for a reason I don’t understand (there are duplicates of two folder making a total of four folders): 2016-04-26 Blick auf das Belchenhotel mit Bergkette90789755 2016-04-26 Blick auf das Belchenhotel mit Bergkette90789755 HGST Travelstar 2.5-Inch 1TB Internal Hard Drive0df1188a HGST Travelstar 2.5-Inch 1TB Internal Hard Drive0df1188a Two subfolders in “Local Folders\Filed Messages” also cannot be permanently deleted. The name of each subfolder appears twice for a total of four folders. 2016-04-26 Blick auf das Belchenhotel, Inh. J. Stiefvater, mit Bergkette36ceb049 2016-04-26 Blick auf das Belchenhotel, Inh. J. Stiefvater, mit Bergkette36ceb049 2016-04-26 Blick auf das Belchenhotel mit Bergkette90789755 2016-04-26 Blick auf das Belchenhotel mit Bergkette90789755 One of the duplicate subfolders can be deleted, but not the other. After exiting/restarting Thunderbird, however, the remaining subfolder can be deleted. I have tried to Repair all of these folders and subfolders before deleting them (Properties\Repair) and, even though I am able to delete them, they reappear after exiting and restarting Thunderbird. I tried to troubleshoot the problem myself using https://support.mozilla.org/en-US/kb/cannot-delete-messages, which suggests the problem might be caused by a corrupted trash folder. In the Thunderbird profile, I opened ImapMail\imap.googlemail.com but did not find the Trash or Trash.msf files, but they are located in [Gmail].sbd (one level lower) – on my computer the location is: C:\0-TBird\Profiles\jsxynuvz.default\ImapMail\imap.googlemail.com\[Gmail].sbd. I renamed the Trash and Trash.msf folders and restarted Thunderbird. When I went back to the [Gmail].sbd folder, neither of the renamed trash files were there, but a new Trash.msf folder had been created. Two folders still remained in “Local Folder\Trash”: 2016-04-26 Blick auf das Belchenhotel mit Bergkette90789755 HGST Travelstar 2.5-Inch 1TB Internal Hard Drive0df1188a and two folder still remained in two different subfolders of “Local Folder\Trash”: 2016-04-26 Blick auf das Belchenhotel, Inh. J. Stiefvater, mit Bergkette36ceb049 2016-04-26 Blick auf das Belchenhotel mit Bergkette90789755 These four folders were all deleted, Thunderbird was closed, and Trash.msf was deleted. When Thunderbird was restarted, these four folders were in their original locations. What can I do to delete these folders? Thank you very much for your help!