#/usr/bin/perl -w
use strict;
open (TMPOUT,">/tmp/somefile");
my $from;
my @recipients;
while (<>) {
   print TMPOUT unless (/^From: /i || /^To: /i);
   ($from = $_) =~ /Some regex to get from/ if (/^From: /i);
}
close (TMPOUT);
open (PASSWD,"/etc/passwd");
while (<PASSWD>) {
    my @fields = split ":" , $_;
    push @recip , $fields[0] unless (#system account);
}
system (cat /tmp/somefile|sendmail -bm -f"$from" "@recips");
unlink "/tmp/somefile";