check-email-mx.pl

#!perl --

## $ perl check-email-mx.pl <email.txt 

use strict;
use warnings;
use Net::DNS;
my %mx;
for(;;){
	my $email = <>;
	last if not $email;
	$email =~ s/[\x0d\x0a]+//;
	next if not $email =~ /(.+?)\@(.+)/;
	my($user,$domain)=($1,$2);
	my $mx_list = $mx{$domain};
	if(not $mx_list){
		my @names = map{ $_->exchange } mx($domain);
		$mx_list = $mx{$domain} = \@names;
	}
	for my $mx (@$mx_list){
		if( $mx =~ /\Q.mailasrvs.pw\E/ ){
			print "$email: $mx\n";
		}
	}
}