emailrelay-check-ipaddress.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-check-ipaddress.js
//
// An example E-MailRelay filter script for Windows that
// verifies the submitting client's IP address. The IP
// address is read from the envelope file. Invalid IP
// addresses are rejected by deleting the two message
// files and exiting with the special exit code of 100.
// Note that this checks the IP address very late in the
// submission process; a firewall or DNSBL check might
// work better.
//
try
{
    var content = WScript.Arguments(0) ;
    var envelope = WScript.Arguments(1) ;
    var fs = WScript.CreateObject( "Scripting.FileSystemObject" ) ;
    var ts = fs.OpenTextFile( envelope , 1 , false ) ;
    var txt = ts.ReadAll() ;
    ts.Close() ;
    var re = new RegExp( "X-MailRelay-Client: (\\S*)" , "m" ) ;
    var ip = txt.match(re)[1] ;
    var ok = ip === "1.1.1.1" ; /// edit here
    if( ok )
    {
            WScript.Quit( 0 ) ;
    }
    else
    {
            WScript.StdOut.WriteLine( "<<not allowed>>" ) ;
            fs.DeleteFile( envelope ) ;
            fs.DeleteFile( content ) ;
            WScript.Quit( 100 ) ;
    }
}
catch( e )
{
    // report errors using the special <<...>> markers
    WScript.StdOut.WriteLine( "<<error>>" ) ;
    WScript.StdOut.WriteLine( "<<" + e + ">>" ) ;
    WScript.Quit( 1 ) ;
}