Finally a feature which I really appreciate – The mutt sidebar patch. FreeBSD ports users need to compiler mail/mutt-devel with WITH_MUTT_SIDEBAR_PATCH=yes.
[buffy] ~> grep mutt-devel /usr/local/etc/pkgtools.conf
'mail/mutt-devel' => 'WITH_MUTT_MAILDIR_HEADER_CACHE=yes WITH_MUTT_SIDEBAR_PATCH=yes',
http://thomer.com/mutt/