Things to add to the release notes for the next full release:

- SASL security layers (encryption) are now supported for the SMTP MTA.
- You can now select the SMTP server and port from either "send" or a
  user's mh_profile (you could always select the server; that option is
  now documented).  These are available via the -server and -port switches.
- All networking code has been modified to use the new networking APIs
  (getaddrinfo and friends).  All networking code (with the exception of
  the ftp client) now supports IPv6.
- Support for prefixing a \01 in the "servers" entry in mts.conf to
  connect to all servers on a particular named net has been removed.