bug#26102: movemail can't connect mail server

[Paul Eggert]

> I'm guessing that you
> are using port 995 because your POP server requires SSL/TLS
> connections, in which case that's another problem: movemail that comes
> with Emacs doesn't support such connections.
How about if we change Emacs so that it relies on GNU Mailutils 
movemail, instead of installing its own movemail? This should help 
prevent similar problems in the future, and should simplify Emacs 
maintenance a bit. These days it's almost malpractice to ship a mail 
client that supports only unencrypted network connections.