Users receive an - One or more of your reminders could not be snoozed or dismissed - error when they dismiss or snooze calendar reminders, how can I fix this?
There are two possible causes for the "One or more of your reminders could not be snoozed or dismissed" error:
The SystemAttendantDN registry key may be missing. Solution: To add the SystemAttendantDN registry key, refer to Microsoft KB 3104440
The value of the user object attribute legacyExchangeDNis incorrect.
Solution: Follow Microsoft KB 556073 to correct the legacyExchangeDNattribute value for affected users. The Global Address Book should be rebuilt after updating the attribute.
NOTE: The Outlook AutoComplete function may continue to use the incorrect legacyExchangeDN value; add the "incorrect" value to the affected user's proxyAddresses attribute to ensure email delivery.