#!/usr/bin/perl
use strict;
use warnings;

my $in_header = 0;
while(<>) {
  if ( $in_header and /^$/ ) {
    $in_header = 0;
  } elsif ( not $in_header and /^From / ) {
    $in_header = 1;
  } elsif ( /^----/ ) {
    $in_header = 1;
  }

  if ( $in_header ) {
    if ( s/^From (\S+)/From marklar\@wfu.edu/ ) { }
    elsif ( s/(on behalf of).*/$1 Marklar/ig ) {} 
    elsif ( not /example/ and s/^(From|To|CC|Reply-To): .*/$1: Marklar <marklar\@wfu.edu>/ ) {}
    elsif ( s/^((Subject|Thread-Topic):\s*(Re: )*\[Example\])\s*.*/$1 Marklar/i ) {}
    elsif ( s/envelope-from \S+\)/envelope-from marklar\@wfu.edu)/ ) {}
    elsif ( s/\b\S+\.dhcp/marklar.dhcp/g) {} 
    s/from \S+/from marklar/g;
  } else {
    s/\b[A-Z]\w*/Marklar/g;
    s/\b[a-z]\w*/marklar/g;
    s/\b\d\w*/MARKLAR/g;
  }
  print;
}