Bite the bullet _now_ and use MTA user exim instead. This means that
only early adopters of Exim-3.31 are affected, rather than lots more
folks further down the line.
I still think mailnull is better, but nobody in the Exim community
agrees with me. :-)
Bump PORTREVISION as appropriate.
Since BSD UNIX still doesn't offer a user for running an MTA in a
sandbox the way many Linux distributions do, the Exim port uses
the traditional sandbox user for sendmail, called 'sendmail'.
Bump PORTREVISION accordingly.
