Question

Does anyone know the format of the MAPI property PR_SEARCH_KEY?

The online documentation has this to say about it:

The search key is formed by concatenating the address type (in uppercase characters), the colon character ‘:’, the e-mail address in canonical form, and the terminating null character.

And the exchange document MS-OXOABK says this:

The PidTagSearchKey property of type PtypBinary is a binary value formed by concatenating the ASCII string ‘EX: ‘ followed by the DN for the object converted to all upper case, followed by a zero byte value.

However all the MAPI messages I’ve seen with this property have it as some sort of binary 16 byte sequence that looks like a GUID. Does anyone else have any more information about it? Is it always 16 bytes?

Thanks!

Answer 1

I believe that the property PR_SEARCH_KEY will be of different formats for different objects (as alluded to by Moishe).

A MAPI message object will have a unique value assigned on creation for PR_SEARCH_KEY, however if the object is copied this property value is copied also. I presume when you reply to an e-mail, Exchange will assign the PR_SEARCH_KEY value to be the original message’s value.

You will need to inspect each object type to understand how the PR_SEARCH_KEY is formed but I doubt if it’s always 16 bytes for all MAPI types.

This link USENET discussion has a good discussion with Dmitry Streblechenko involved who is an expert on Extended MAPI.