Let Postfix speak to br0ken systems

Microsoft has a bug in its implementation of RFC 1854. The only way to deliver mail with Postfix to such a broken mail system is to dumb down Postfix: smtp_never_send_ehlo = yes

Microsoft also has instructions on how to dumb down ESMTP (even more): Disabling Inbound ESMTP Advertisement here

Configuring this MTA feature requires editing the Windows registry. The article says:

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved.

Changing an MTA setting and having to reinstall the entire operating system if you make a mistake?
No wonder that Microsoft is campaigning that UNIX is difficult to use and inflexible.

Recommended Setup

In master.cf copy the line starting with and ending in smtp not smtpd and rename it to brokensmtp by changing the first column from smtp to brokensmtp and give it special options:

brokensmtp  unix ... smtp -o smtp_never_send_ehlo=yes

Then create a special transport entry in tranport_maps for the br0ken system:

pva.pt                               brokensmtp:[some.ip.add.ress]
other.broken.esmtp.implementation    brokensmtp:

© by Ralf Hildebrandt
This document contains links to external information sources that I do neither monitor nor control. I explicitly disclaim any liabilities in respect to external references.
You are getting this document without any guarantees. Any methods shown above are meant as demonstration and may be wrong in some place. You may damage your system if you try to follow my hints and instructions. You do this at your own risk!

This file was last modified 24. Sep 2007 by root