Sorry about the lack of replies to questions in this list. Work on the new indexing code has taken way too long, but it's finally beginning to be get near usable state. After it's fully working, I'll start being more active here again.

If you're interested (as a developer, normal users shouldn't even try playing with it yet), you can checkout "newdove" module from Dovecot CVS. Many things are still broken, but basic maildir support is almost working with the exception of expunges (which probably break badly) and custom flags (not implemented). And the maildir syncing code isn't optimized yet.

Don't try it with any of your real maildirs, it might lose your mails.

Some of the new great things in it:

• Mailbox API which is a lot more easier to use than before, allowing a lot of things that previously were difficult to implement
• Less IMAP-specific than before
• Should work extremely well with shared mailboxes with tons of users

I'm hoping to get a usable alpha release out of it within few weeks.