Mail::Verify - Utility to verify an email address

Mail-Verify documentation Contained in the Mail-Verify distribution.

Index

Code Index:

NAME

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Mail::Verify - Utility to verify an email address

SYNOPSIS

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    use Mail::Verify;

DESCRIPTION

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Mail::Verify provides a function CheckAddress function for verifying email addresses. First the syntax of the email address is checked, then it verifies that there is at least one valid MX server accepting email for the domain. Using Net::DNS and IO::Socket a list of MX records (or, falling back on a hosts A record) are checked to make sure at least one SMTP server is accepting connections.

ERRORS

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Here are a list of return codes and what they mean:

The email address appears to be valid.

No email address was supplied.

There is a syntaxical error in the email address.

There are no DNS entries for the host in question (no MX records or A records).

There are no live SMTP servers accepting connections for this email address.

EXAMPLES

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This example shows obtaining an email address from a form field and verifying it.

  use CGI qw/:standard/;
  use Mail::Verify;
  my $q = new CGI;
  [...]
  my $email = $q->param("emailaddr");
  my $email_ck = Mail::Verify::CheckAddress( $email );
  if( $email_ck ) {
      print '<h1>Form input error: Invalid email address.</h1>';
  }
  [...]
Mail-Verify documentation Contained in the Mail-Verify distribution. 
# Mail::Verify.pm
# $Id: Verify.pm,v 1.4 2002/06/09 15:42:32 petef Exp $
# Copyright (c) 2001 Pete Fritchman <petef@databits.net>.  All rights
# reserved.  This program is free software; you can redistribute it and/or
# modify it under the same terms as Perl itself.

package Mail::Verify;


use strict;
use IO::Socket;
use Net::DNS;

my $VERSION = "0.02";
my $DEBUG = "0";

sub Version { $VERSION }

sub CheckAddress {
    my $addr = shift;
    return 1 unless $addr;

    my ($rr, @mxhosts, @mxrr, $resolver, $dnsquery, $livesmtp, $mx);
    my ($testsmtp);

    # First, we check the basic syntax of the email address.
    my ($user, $domain, $extra);
    ($user, $domain, $extra) = split /\@/, $addr;
    return 2 if $extra;
    @mxrr = Net::DNS::mx( $domain );
    # Get the A record for each MX RR
    foreach $rr ( @mxrr ) {
	push( @mxhosts, $rr->exchange );
    }
    if( ! @mxhosts ) { # check for an A record...
	$resolver = new Net::DNS::Resolver;
	$dnsquery = $resolver->search( $domain );
	return 3 unless $dnsquery;
	foreach $rr ($dnsquery->answer) {
	    next unless $rr->type eq "A";
	    push( @mxhosts, $rr->address );
	}
	return 3 unless @mxhosts;
    }
    # DEBUG: see what's in @mxhosts
    if( $DEBUG ) {
	foreach( @mxhosts ) {
	    $mx = $_;
	    print STDERR "\@mxhosts -> $mx\n";
	}
    }
    # make sure we have a living smtp server on at least one of @mxhosts
    $livesmtp = 0;
    foreach $mx (@mxhosts) {
	$testsmtp = IO::Socket::INET->new(	Proto=>"tcp",
						PeerAddr=> $mx,
						PeerPort=> 25,
						Timeout => 10
					);
	if( $testsmtp ) {
	    $livesmtp = 1;
	    close $testsmtp;
	}
    }
    if( ! $livesmtp ) {
	return 4;
    }
    return 0;
}

1;