Consider the following scenario:
Multiple users edit and save a public folder item at the same time in a Microsoft Exchange Server 2010 environment.
Note When this occurs, a conflict message is sent to the public folder owner.
The public folder owner opens the conflict message attachment, and then chooses to keep one item by using Microsoft Office Outlook.
In this scenario, all the conflict items that are listed in the conflict message attachment are kept. If the conflict items are digitally signed, public folder replication fails. Additionally, the following events are logged in the Application log:
This issue occurs because the attachment table of the selected item does not replace the attachment table of all the conflict items successfully.
To resolve this issue, install the following update rollup:
2579150 Description of Update Rollup 4 for Exchange Server 2010 Service Pack 1
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.