Three folders in “Local Folders\Trash“ cannot be permanently deleted. They can be deleted but, after exiting and restarting Thunderbird, they appear again in “Local Folders\Trash“. [See the attached image file, 2018-07-17 Can't delete folders_1.jpg] These folders have 8-character suffixes added by Thunderbird for reasons I don’t understand: 2016-04-26 Blick auf das Belchenhotel mit Bergkette90789755 HGST Travelstar 2.5-Inch 1TB Internal Hard Drive0df1188a Website programmers, subcontractors, helpers, etcd756875c Folders and subfolders in “Local Folders\Filed Messages” also cannot be deleted. [See the attached image file, 2018-07-17 Can't delete folders_2.jpg] The folder name, "Website programmers, subcontractors, helpers, etc.", appears six times, four times with the Thunderbird suffix, d756875c. Thunderbird created the folder names with the suffix two times as subfolders of the folder, "Silicon Valley Computer Genealogy Group". I originally created a folder, "Website programmers, subcontractors, helpers, etc.", at the same directory level as Silicon Valley Computer Genealogy Group. Thunderbird created a folder with the same name at the same level and added subfolders to both of them with the name, "Website programmers, subcontractors, helpers, etcd756875c". I used the procedure suggested in "Cannot delete messages" (https://support.mozilla.org/en-US/kb/cannot-delete-messages#thunderbird:win10:tb52), but that did not solve my problem. How can I delete these folders permanently? And why are suffixes added by Thunderbird to both folders and file names? Thank you very much for your help!