Article ID: 2488643 - View products that this article applies to.
Consider the following scenario:
In this scenario, Outlook downloads all POP3 email messages every time it starts. Therefore, duplicated POP3 email messages are in the mailbox.
Note You expect Outlook to download these messages only once.
The issue occurs because the Microsoft Exchange RPC Client Access service on the Exchange Server 2010 Client Access Server (CAS) role incorrectly overwrites the long attachment file name to an 8.3 short name. Because of this issue, Outlook cannot determine which POP3 messages were downloaded. Therefore, Outlook downloads all POP3 messages every time it starts.
To resolve this issue, install the following update rollup:
(https://support.microsoft.com/kb/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.
For more information about RPC client access, visit the following Microsoft Developer Network (MSDN) website:
General information about understanding RPC client access
For more information about attachment properties, visit the following Microsoft Developer Network (MSDN) website:
General information about attachment properties
Article ID: 2488643 - Last Review: June 21, 2014 - Revision: 4.0