`emailrelay-list-verify.pl <emailrelay-list-verify.pl>`_
--------------------------------------------------------

.. code:: perl

    #!/usr/bin/env perl
    #
    # SPDX-FileCopyrightText: 2026 Graeme Walker <graeme_walker@users.sourceforge.net>
    # SPDX-License-Identifier: FSFAP
    # 
    # Copyright (c) 2026 Graeme Walker <graeme_walker@users.sourceforge.net>
    # 
    # Copying and distribution of this file, with or without modification,
    # are permitted in any medium without royalty provided the copyright
    # notice and this notice are preserved.  This file is offered as-is,
    # without any warranty.
    # ===
    #
    # emailrelay-list-verify.pl
    #
    # An example E-MailRelay address verifier script that uses
    # a hard-coded list of recipient addresses.
    #
    
    use strict ;
    
    my ( $to, $from, $ip, $domain, $mechanism, $id ) = @ARGV ;
    
    # list of recognised recipient addresses
    #
    my %users = (
    	alice => '' , # valid
    	bob => '' , # valid
    	carol => 'carol.smith@'.$domain , # valid, with mapping
    	dave => _local("david") , # local mailbox
    	erol => _local() , # local mailbox
    	malory => undef , # abort
    ) ;
    sub _local { return \$_[0] }
    
    # split the recipient address and check the domain part
    my ( $user_part , $domain_part ) = ( $to =~ m/([^@]+)@(.*)/ ) ;
    if( lc($domain_part) ne lc($domain) )
    {
    	print "invalid address\n" ;
    	print "invalid domain-part [$domain_part]\n" ;
    	exit( 2 ) ;
    }
    
    # case-insensitive match of the user part
    my ($user) = grep { lc($user_part) eq lc($_) } keys %users;
    
    if( ref($users{$user}) )
    {
    	# valid local recipient address with a mailbox
    	my $mailbox = ${$users{$user}} ;
    	$mailbox ||= $user_part ;
    	print $to , "\n" ;
    	print $mailbox , "\n" ;
    	exit 0 ;
    }
    elsif( defined($users{$user}) )
    {
    	# valid recipient address
    	my $address = $users{$user} || "$user_part\@$domain" ;
    	print "\n" ;
    	print $address , "\n" ;
    	exit 1 ;
    }
    elsif( defined($user) )
    {
    	# abort
    	exit 100 ;
    }
    else
    {
    	print "invalid address\n" ;
    	print "invalid user-part [$user_part]\n" ;
    	exit 2 ;
    }
    

.. _../examples/emailrelay-list-verify.pl: emailrelay-list-verify_pl.html