Microsoft Outlook-Exchange Transport Protocol

In January, Microsoft licensed the Outlook-Exchange Transport Protocol.

There are three elements to this:

  • Detailed documentation of MAPI. This is a very rich set of APIs for accessing Outlook information: emails, calendar items, directory entries, etc.
  • Detailed documentation on how to write MAPI service providers. This lets third parties offer their services, and be accessible via MAPI calls. In addition, Microsoft sells licenses to write such service providers. We understand the fees are very modest.
  • Detailed documentation on how to encapsulate MAPI in an on-the-wire protocol (aka MAPI/RPC).

Fifteen years ago:

  • Documentation for MAPI was available, if you knew whom to ask. It was very long, indescribably boring (like most API documentation), and rather incomplete (because of the complexity of fully modeling the messaging environment).
  • Documentation for the service provider interface was also available. Like fine French lingerie, it was incredibly skimpy.
  • Documentation for MAPI/RPC wasn’t ever published.

Our overall sense of what has happened is this:

  • MAPI and service provider documentation was allowed to whither, and was withdrawn.
  • It was resurrected in response to a mandate from the European Commission, but most people still found it unhelpful.
  • Now Microsoft is applying proper resources to maintain the documentation and interfaces.

All in all, a good development–it’s good that MAPI and its service provider interfaces should be well documented and supported.

PS. Several people at Ferris Research — David Ferris and Richi Jennings, and perhaps Nick Shelness — read the original MAPI and service provider documentation. It is perhaps a sad reflection upon our lives that we enjoyed doing so — we found it fun — and would indeed enjoy browsing the updated material. 🙁

David Ferris, with Richi Jennings

One Comment

  1. Posted March 21, 2007 at 6:22 AM | Permalink

    Cemaphore Systems is the first reference licensee of this protocol, and has been using this protocol in its series of MailShadow(R) products. Using this protocol enables a true application aware method for Disaster Recovery for Exchange. The benefit is that you can deliver complete mailbox content by the mailbox. Here is the Microsoft approved press release:

    http://www.cemaphore.com/press_release_20070321.php

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