Per Matt Palmer’s blog entry OfflineIMAP and Deleting Folders users of any mail sorting recipe that creates new mail folders a lot tend to find that over time they accumulate a lot of mail folders for, eg, email lists they are no longer subscribed to. And most IMAP clients will waste time checking those folders for new mail all the time.
Now, of course, someone’s going to point me to a small script that finds all of your local empty folders and deletes them locally then issues an IMAP “delete folder” command on the server. But I had fun working all this out, so it’s not a complete waste.
I haven’t quite done this, I’ve just written a script that detects and deletes empty remote folders. (For me, offlineimap does not have the behaviour of creating new remote folders, so I haven’t bothered cleaning up local folders.)
It’s good: it’s speeding up my mail syncs a whole lot, deleting these old folders I haven’t received mail in for about five years. I’ve got full details and the script available for download (as you’d expect, it’s short): Python script to delete empty IMAP folders.