IMAP upgrade - new features

Our IMAP server (Cyrus) has been upgraded to a new version, which includes some additional features we commissioned:

1. Fuzzy folder matching in delivery. When you use the + or sub-domain
   addressing,
   folders are now matched, and if not found, a fuzzy match is done. In
   the fuzzy match scenario, folders are compared in a case insensitive
   way, and with the chars “-”, “_” and " " (space) all treated as the
   same. So if you have a folder “Mailing Lists.My List”, then sending
   to username+mailing-lists.my_list@domain.tld will get filed into
   that folder
2. File to parent if sub-folder missing. If in the matching scenario,
   the sub-folder still isn’t found, but a parent folder is, that
   folder is delivered to instead. So if you sent to
   username+mailing-lists.blahblahblah@domain.tld, the email would go
   into the “Mailing Lists” folder, rather than the inbox
3. POP to sub-folders. If you login via POP with the username
   “username+foldername”, then you’ll be able to POP messages from that
   subfolder, not just inbox. This currently doesn’t work for folders
   with spaces in the name unfortunately.
4. Faster message moving/deleting. Internally cyrus now uses a “delayed
   expunge” mode. In small folders, this won’t make much difference,
   but in large folders, it makes moving or deleting messages quite a
   bit faster.

For more information, see this discussion on the forum.