Article ID: 2779387 - View products that this article applies to.
Consider the following scenario:
This issue occurs because the Exchange store sets different values for the PR_INTERNET_MESSAGE_ID property of an opened message item and a submitted message item. After the EWS-based application synchronizes the message items with the Mailbox server, duplicates of the same email messages but with different PR_INTERNET_MESSAGE_ID properties are displayed in the Sent Items folder.
To resolve this issue, install the following update rollup:
(https://support.microsoft.com/kb/2746164/ )Description of Update Rollup 6 for Exchange Server 2010 Service Pack 2
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about the PR_INTERNET_MESSAGE_ID property, go to the following Microsoft website:
General information about the PR_INTERNET_MESSAGE_ID propertyFor more information about this issue, click the following article numbers to view the articles in the Microsoft Knowledge Base:
(https://support.microsoft.com/kb/2592398/ )Email messages in the Sent Items folder have the same PR_INTERNET_MESSAGE_ID property in an Exchange Server 2010 environment
(https://support.microsoft.com/kb/924213/ )Message id is different for mail which is in Inbox & Sent items
Article ID: 2779387 - Last Review: February 22, 2013 - Revision: 4.0