I'm fairly sure they announced it on this list some time back. For me, it solves the issue of wanting to use the command-line for mail in general but also being able to access mail from a mobile phone (or HTML capable mail client) using Maildir backed dovecot and IMAP.
The basic approach of having what would be a sequence in MH implemented as a file containing a list of message files works well. Being able to get a threaded list of messages is really useful, and fast. Integration with other tools like notmuch for searching is easier than for nmh. I still use nmh for viewing and composing messages via wrapper shell functions, however. mblaze lacks the flexibility of mh-format and the hard coded defaults weren't to my taste. But it is a very capable tool. Oliver
