Next qmail 7

Sendmail

Long history of security problems
Infamously horrendous configuration language


SMailerToTriple=95
R< > $*                          $@ $1                   strip off null relay


R< error : $-.$-.$- : $+ > $*    $#error $@ $1.$2.$3 $: $4
R< error : $- : $+ > $*          $#error $@ $(dequote $1 $) $: $2
R< error : $+ > $*               $#error $: $1
R< local : $* > $*               $>CanonLocal < $1 > $2
R< $~[ : $+ @ $+ > $*<$*>$*      $# $1 $@ $3 $: $2<@$3>  use literal user
R< $~[ : $+ > $*         $# $1 $@ $2 $: $3       try qualified mailer
R< $=w > $*                      $@ $2                   delete local host
R< $+ > $*                       $#relay $@ $1 $: $2     use unqualified mailer

Excessively complicated internals
Many ill-advised and unnecessary features