+++ This bug was initially created as a clone of Bug #1130277: "No obvious way to expunge imap maildir folder" +++

With post-102 dailies and betas there has become again no way to immediately expunge or compact out messages in maildir folders that are marked as deleted (crossed out). With I02 and earlier it was possible to do this with the File | Compact Folders menu item, even though it actually iterated though all the imap folders, compacting all of them and not just the currently selected folder. Now when a imap based maildir folder is selected the "Compact Folders" File menu item is grayed out (and the right-click context doesn't show "Compact") so there is no way to expunge the crossed out messages.

It also appears the File | Compact Folders, when not gray, now only initiates compact and imap expunge on the currently selected folder, not on ALL folders as the name implies and how it actually worked with 102 and earlier. If this is not a regression and that is the intended new usage for File | Compact Folders it should be labeled "File | Compact Current Folder" or "File | Compact Folder" since it now only affects a single currently selected folder.

The attached diff allows the "File | Compact Folders" to be un-grayed and the right-click context item "Compact" on an imap maildir folder to be visible and perform the needed imap expunge and removal of the permanently deleted message files from maildir's "cur" directory. This is basically the same diff as was attached and described at bug 1130277 that this bug was cloned from.
This diff doesn't address the possible regression that "File | Compact Folders" only affects the selected folder.

xref bug 1823546

From comment 0:

With I02 and earlier it was possible to do this with the File | Compact Folders menu item, even though it actually iterated though all the imap folders, compacting all of them and not just the currently selected folder.

To be exact I should have said "it actually iterated though all the imap folders of the currently selected account, compacting all of them and not just the currently selected folder".