#!/usr/bin/perl -w

#checks for valid email address
#usage validemail <file containing email addresses>

use warnings;
use strict;
use Email::Valid::Loose;
use Net::DNS;
use Parallel::ForkManager;

my $pm=new Parallel::ForkManager(20);
my $resolver=Net::DNS::Resolver->new();
my $addrfile = $ARGV[0];
my ($is_valid, $host, $ip, @goodaddr, @badaddr, $x, $record, @mx, $add, @adds);

#custom words that make emails invalid to you
my @custom = qw(
 postmaster
 webmaster
);
  

open (EMAILS, "$addrfile");

 while (<EMAILS>){
 $_ =~ s/\015//;
 chomp $_;
    push @adds, $_;
}
close (EMAILS);

OUTER: foreach $add (@adds){ 
    
    $pm->start and next;

    foreach $x (@custom){
            if ($add =~ m/$x/){
                push (@badaddr, $add);
                next OUTER;
            }
        }

        #if email is invalid move on
        if (!defined(Email::Valid::Loose->address($add))){
            push (@badaddr, $add);
            next OUTER;
        }

        #if email is valid get hostname
        $is_valid = Email::Valid::Loose->address($add);
        if ($is_valid =~ m/\@(.*)$/) {
            $host = $1;
        }
        $is_valid="";
        
        # perform dsn lookup to check domain
        @mx=mx($resolver, $host);

        if (@mx) {
            push (@goodaddr, $add); #address is good
            }else{
            push (@badaddr, $add); #address is bad
        }
       
    $pm->finish;
}


#warning! I will delete existing files as I open them!

open (BADADDR, ">badmails") || die;
foreach $x (@badaddr){
 print BADADDR "$x\n";
}
close (BADADDR);

open (GOODADDR, ">goodmails") || die;
foreach $x (@goodaddr){
 print GOODADDR "$x\n";
}
close (GOODADDR);