This patch adds ESMTP relay support to mutt.
To use, set $smtp_url to the address of your smtp relay, in the form:
smtp[s]://[user[:password]@]host[:port]/
where port defaults to 25 for smtp and 465 for smtps.
You can also set $smtp_authenticators to control which methods mutt
will attempt to use during authentication. See $imap_authenticators
for details.
