the orginal Heirloom mailx, formerly nail, is unmaintained, but
Steffen Nurpmeso has created a fork called s-nail [1] and has
added a lot of fixes to the mailx codebase.
After using that for several months, I got the feeling that we
can and should use that fork for our mailx port.
[1] http://sdaoden.users.sourceforge.net/code.html