emailrelay-set-message-id.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-set-message-id.js
//
// An example E-MailRelay filter script that sets a
// message-id header if there is none. Recent versions of
// emailrelay have a built-in filter "msgid:" to do this.
//
try
{
    var domain = "example.com" ;

    var content = WScript.Arguments( 0 ) ;
    var fs = WScript.CreateObject( "Scripting.FileSystemObject" ) ;
    var in_ = fs.OpenTextFile( content , 1 , false ) ;
    var out_ = fs.OpenTextFile( content + ".tmp" , 8 , true ) ;

    var re_message_id = /^Message-ID:/i ;
    var re_fold = /^[ \t]/ ;

    var in_message_id = 0 ;
    var have_message_id = 0 ;
    while( !in_.AtEndOfStream )
    {
            var line = in_.ReadLine() ;
            if( line === "" )
            {
                    if( !have_message_id )
                    {
                            var now = new Date() ;
                            var lhs = (now.getTime()/1000) + "." + (Math.random()*1000).toFixed(0) ;
                            var new_message_id = lhs + "@" + domain ;
                            out_.WriteLine( "Message-ID: " + new_message_id ) ;
                    }
                    out_.WriteLine( line ) ;
                    break ;
            }

            if( line.match(re_message_id) )
            {
                    have_message_id = 1 ;
                    in_message_id = 1 ;
            }
            else if( in_message_id && line.match(re_fold) )
            {
            }
            else
            {
                    in_message_id = 0 ;
                    out_.WriteLine( line ) ;
            }
    }
    while( !in_.AtEndOfStream )
    {
            var body_line = in_.ReadLine() ;
            out_.WriteLine( body_line ) ;
    }

    in_.Close() ;
    out_.Close() ;
    fs.DeleteFile( content ) ;
    fs.MoveFile( content + ".tmp" , content ) ;

    WScript.Quit( 0 ) ;
}
catch( e )
{
    WScript.StdOut.WriteLine( "<<edit failed>>" ) ;
    WScript.StdOut.WriteLine( "<<" + e + ">>" ) ;
    WScript.Quit( 1 ) ;
}