emailrelay-list-verify.js

//
// 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.js
//
// An example E-MailRelay address verifier script for
// Windows that uses a hard-coded list of recipient
// addresses.
//
try
{
    var to = WScript.Arguments(0) ;
    //var from = WScript.Arguments(1) ;
    //var ip = WScript.Arguments(2) ;
    var domain = WScript.Arguments(3) ;
    //var mechanism = WScript.Arguments(4) ;
    //var id = WScript.Arguments(5) ;

    // list of recognised recipient addresses
    //
    var users = [
            ["alice",""] , // valid
            ["bob",""] , // valid
            ["carol","carol.smith@"+domain] , // valid, with mapping
            ["dave","@david"] , // local mailbox, with mapping
            ["erol","@"] , // local mailbox
            ["malory","@@"] // abort
    ] ;

    // split the recipient address and check the domain part
    var re = new RegExp( "([^@]*)@(.*)" ) ;
    var user_part = to.match(re)[1] ;
    var domain_part = to.match(re)[2] ;
    if( domain_part.toLowerCase() !== domain )
    {
            WScript.StdOut.WriteLine( "invalid address" ) ;
            WScript.StdOut.WriteLine( "invalid domain-part ["+domain_part+"]" ) ;
            WScript.Quit( 2 ) ;
    }

    // case-insensitive match of the user part
    var user_key = "" ;
    var user_value = "" ;
    for( var i = 0 ; i < users.length ; i++ )
    {
            var user = users[i] ;
            if( user_part.toLowerCase() === user[0].toLowerCase() )
            {
                    user_key = user[0] ;
                    user_value = user[1] ;
                    break ;
            }
    }

    if( user_value.charAt(0) === '@' && user_value !== "@@" )
    {
            // valid local recipient address with a mailbox
            var mailbox = user_value === "@" ? user_key : user_value.substr(1) ;
            WScript.StdOut.WriteLine( to ) ;
            WScript.StdOut.WriteLine( mailbox ) ;
            WScript.Quit( 0 ) ;
    }
    else if( user_key.length && user_value !== "@@" )
    {
            // valid recipient address
            var address = user_value.length ? user_value : (user_part+"@"+domain) ;
            WScript.StdOut.WriteLine( "" ) ;
            WScript.StdOut.WriteLine( address ) ;
            WScript.Quit( 1 ) ;
    }
    else if( user_value === "@@" )
    {
            // abort
            WScript.Quit( 100 ) ;
    }
    else
    {
            WScript.StdOut.WriteLine( "invalid address" ) ;
            WScript.StdOut.WriteLine( "invalid user-part ["+user_part+"]" ) ;
            WScript.Quit( 2 ) ;
    }
}
catch( e )
{
    WScript.StdOut.WriteLine( "error" ) ;
    WScript.StdOut.WriteLine( e.name + ": " + e.message ) ;
    WScript.Quit( 3 ) ; // temporary failure
}