Retaining X.400 Connectivity for Exchange 2007/2010

X.400 is a suite of email protocols that are now considered legacy by.. well.. almost everyone. In decades gone by X.400 competed with the SMTP protocol for domination of the email world.  The argument was one of performance and reliability (X.400) versus ease of deployment and use (SMTP).  SMTP ultimately won this battle as the ease of deployment generally proliferated the product, everywhere. Once in general use, the performance and reliability issues were tackled, eventually sounding the victory horn for SMTP over X.400.

The problem is that X.400 is just one of those protocols that refuses to die, and it will continue to be a slow and steady migration as it disipates. There are certainly many automated mail systems out there, that are simply not being upgraded, because the message transports are transparent to the users and many organisations take the approach of, “well, if it ain’t broke, why fix it”.

Microsoft Exchange 2003 And X.400 Support

In earlier versions of the Microsoft Exchange, X.400 support was inherently provided as part of the core MTA.  Microsoft Exchange 2003, for instance, had an X.400 MTA and Exchange users could send messages to X.400 recipients via configurable X.400 connectors.  This MTA and X.400 connector support was completely removed from Exchange 2007.  Considered a legacy technology by Microsoft, they decided to completely remove support for sending messages in the X.400 format moving forward.

While this support is no longer needed in 99% of Exchange implementations, it does cause serious issues, for those systems that require X.400 connectivity to talk to legacy email systems, or older automation systems which utilise an underlying Exchange to X.400 transport mechanism.

Microsoft Exchange 2007/2010 and Using Exchange 2003 Co-existence To Support X.400

One option that was available for organisations who need to retain X.400 support is to Upgrade the core Exchange server to 2007, but to keep one Exchange 2003 server to act as a gateway to the legacy X.400 environment. This does work, but it is messy, messy, messy.

First of all, between Exchange 2003 and 2007, the transport and routing architecture has be completely revamped. In Exchange 2003, there was a concept of grouping servers together in Routing Groups. Routing Groups were configured completely independently of physical or other constraints, thus giving the administrator more granular control over routing.

To retain X.400 support while moving to 2007/2010 we must install our new 2007/2010 server into an existing Exchange 2003 organisation. A special routing group is created that contains your entire 2007/2010 environment. Doing this allows us to pump messages via the remaining single 2003 server which can then convert to X.400.

There are several problems with this approach, the main one being:

  • Exchange 2003 has just (or is about to) be end of life’d, and unsupported in future.
  • The administrative overhead of keeping the co-existence environment running is significant.
  • There is no option for putting an Exchange 2003 server into a 2007/2010 organisation. It can only be done one way, retrofitting isn’t an option.
  • There will be no technical option to do this in the new version of Exchange (Exchange 15). So if 2007/2010 are deployed in this way, a complete reinstall will be required when upgrading to E15. So X.400 support will be lost anyway.

Keeping Exchange 2007/2010 X400 Support The Easy Way

Boldon James has worked with X.400 solutions for over 20 years. We have been very tightly involved with Microsoft in this area for the last 16 years. You may even find that some of the code within the Exchange 2003 X.400 MTA has been written ans supported by Boldon James.

Since Exchange 2007 was released, we have developed and released our X.400 Bridgehead Server for Exchange 2007 and subsequently our X.400 Bridgehead Server for Exchange 2010.  Our Bridgehead Server is deployed on the Hub Transport role of the Exchange system and is considered what MS call a foreign connector.

It provides a light and easy approach to implementing X.400 connectivity in any 2007 and 2010 Exchange organisation.  This means that is can be deployed in new installations as well as old. It sits on a fully supported Microsoft platform (2007 and 2010) and provides assurance that X.400 capability will still be available on future platforms such as Exchange 15.

If you would like to learn more about the Boldon James X.400 Bridgehead for Microsoft Exchange, or to request and evaluation. Please feel free to contact me. Or contact Boldon James at

Leave a Reply

You can use these HTML tags

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>