Consider the following scenario in a Microsoft Exchange Server 2007 environment:
You send a recurring meeting request to some attendees.
You update several occurrences by adding additional attendees.
You cancel some or all of these occurrences by changing the appointment recurrence pattern.
In this scenario, if you perform these operations by using Exchange Web Service (EWS) application, the additional attendees do not receive a meeting cancellation notification.
Note If you perform these operations by using Microsoft Office Outlook or Outlook Web Access (OWA), all attendees including the additional attendees receive a meeting cancellation notification as expected.
To resolve this problem, install the following update rollup:
972076 Description of Update Rollup 2 for Exchange Server 2007 Service Pack 2
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.