Registering custom url protocl handler that Outlook recognizes?

Question

Good morning,

I've successfully created a little app that registers itself under a custom uri protocol ('irma:') following the msdn entry at http://msdn.microsoft.com/en-us/library/aa767914(VS.85).aspx

This works perfectly fine when opening such a link manually via the shell/cmd etc, but when sending out links like that, outlook does not recognize those 'automatically' on the clients that registry key is set. Do I have to do something extra to let outlook handle such custom uri's or is it possible at all?

Cheers and thanks, -j

Answer 1

Update: The information presented below appears to be outdated by now. See my other answer.

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I've done some research on this in the past and came to the conclusion that it's not possible. The protocols that Outlook is able to "auto-linkify" are apparently hard-coded. The results of my previous research are documented in this newsgroup thread:

How to make custom APPs recognizable by Outlook/Word/...
(posted April-June 2005 on microsoft.public.inetsdk.programming.urlmonikers)

Quote from MS product support:

Unfortunately the Hyperlink recognition in Office - so that auto format automatically transforms the entered text into a hyperlink - is hard coded.
Therefore you can't add new protocols to the recognition.

See the last post in that thread for my summary of the differences in URL-recognition between the various Office programs (hint: Outlook supports the fewest protocols).

Here's the relevant bits regarding Outlook. The following patterns are automatically recognized as links by Outlook (as of June 2005, i.e. Outlook 2003):

1. if first word of a hyperlink is

   • "www" (e.g. www.microsoft.com)
   • "ftp" (e.g. ftp.microsoft.com)

2. If hyperlink starts with one of the following expressions followed by ":/"

   • http
   • https
   • ftp
   • gopher
   • prospero
   • telnet
   • wais
   • file

3. if hyperlink starts with one of the following expressions followed by ":" and a string (e.g. mailto:blah)

   • mailto
   • news
   • nntp
   • outlook

Answer 2

[OK, I'll post this as a new answer to keep this one clean without deleting all of the previously posted content.]

I have just repeated the research mentioned in my other answer and it seems that things have greatly improved in the last three years. Both Outlook 2003 (SP3) and Outlook 2007 (SP2) now automatically recognize all of the protocols listed in the MS product support mail quoted in the NG thread linked from my older answer, including the url:-protocol!

The latter means that you can now write something like:

url:irma:whatever

and have it properly linkified and handled. Outlook will however display a security confirmation dialog before executing the protocol handler.

Update: Note that in Outlook 2003 SP3 the new protocols (e.g. url:, mms://, etc.) are only auto-linkified in HTML-mails. The plain-text inspector behaves as described in my other answer. It does work with plain-text mails in Outlook 2007 SP2, however.

I have still found no hints at the ability to simply register custom protocols within Outlook that would work without the url:-prefix, however.