Exchange: Is it possible to search for a custom Extended Property across all mailboxes?

Question

My team and I are in the process of integrating our custom CRM (built entirely on the MS stack) with Exchange. A key part of that integration is binding Exchange items (namely meetings and tasks) to customer records. Basically, when a salesperson schedules a meeting with a certain customer, the customer's GUID is attached to that meeting as a custom extended property. Simple enough, right?

When we are dealing with a single mailbox, searching for a custom extended property is easy. But what about multiple mailboxes e.g., searching all salesperson calendars for meetings that have a certain customer's GUID attached as a custom extended property?

Is it possible to search across all (or several) mailboxes for a given custom extended property? Is binding our data using custom extended properties even the correct approach?

---

Environment: We're using the EWS Managed API to talk to an Exchange 2010 server. Exchange 2007 EWS with auto-gen proxies function in the same general manner, however, so suggestions relating to 2007 should be applicable.

Answer 1

There isn't a way to do a search across multiple mailboxes at once. You'll need to connect into each mailbox individually and do the search that way.