The functionality and difficulties associated with using DASL tables in VSTO add-ins are critical for developers who want to improve Outlook's functionality. When trying to follow messages from particular senders, irregularities appear, most often because different PCs have different Outlook configurations. We also look at the complexity of the Microsoft MAPI structure and how it affects the dependability of DASL queries.

This article addresses the problem of locating particular contacts in Microsoft Outlook using a VSTO Add-In and walks through the use of DASL queries to retrieve contact details. In order to retrieve and count instances of particular data across several Outlook accounts, the method includes querying MAPI properties.