Release Notes: Essentially a rewrite: synchronization state storage concept, configuration, and the command line have changed entirely. A fully automated migration path is provided. The supported mailbox types can be freely paired. Message expunges are now propagated both ways, so there is no need for using mutt with maildir_trash any more. Additional trash options have been added. 'OneToOne' has been replaced with something more flexible. There is partial support for IMAP pipelining.
Release Notes: Support was added for CRAM authentication, uploading of messages in the local mailbox to the server, and an option to move deleted messages to a specific folder on the IMAP server. The SSL support is now much more configurable for use with older IMAP servers.