Hi. We are using 140.1.1esr 64 bit. We have a very large (70+ GB) pop Mail folder, with hundreds of folders. The folders are not under Inbox but under the account name itself. Items are moved to the folders through drag and drop. We have qn issue where adding items to a folder can cause it to disappear, and a sorting problem where the alphabetical list of folders starts over again. The screenshot shows the sorting issue. We have tried: Repeatedly removing msf files. Deleting folderlist.json, and index file in Mail. Latest try was deleting folderlist.json, and global-messages-db.sqlite, and everything from mail folder except mbox files. This seemed to work at first, but still having problems with the alphabetized list starting over again, folders disappearing after moving items between them. Also have some mbox files that appear to have mail in them, can read it with notepad, but do not create folders when copied back to Mail or Local Folders. Looking for suggestions as we don’t seem to be getting anywhere. Thanks.