Update Rollup 4 for Exchange Server 2010 SP2 resolves the issues that are described in the following Microsoft Knowledge Base (KB) articles:
2536846 Email messages sent to a mail-enabled public folder may be queued in a delivery queue on the Hub Transport server in an Exchange Server 2010 environment
2632409 Sent item is copied to the Sent Items folder of the wrong mailbox in an Exchange Server 2010 environment when a user is granted the Send As permission
2637915 "550 5.7.1" NDR when an email message is sent between tenant organizations in a multi-tenant Exchange Server 2010 environment
2677727 MRM cannot process retention policies on a cloud-based archive mailbox if the primary mailbox is in an on-premises Exchange Server 2010 organization
2685001 Retention policies do not work for the Calendar and Tasks folders in an Exchange Server 2010 SP1 environment
2686540 Journal report is not delivered to a journaling mailbox in an Exchange Server 2010 environment
2689025 Performance issues when you use the light version of Outlook Web App in an Exchange Server 2010 environment
2698571 Some email messages are not delivered when you set the MessageRateLimit parameter in a throttling policy in an Exchange Server 2010 environment
2698899 Add-ADPermission cmdlet together with a DomainController parameter fails in an Exchange Server 2010 environment
2700172 Recipient’s email address is resolved incorrectly to a contact’s email address in an Exchange Server 2010 environment
2701162 User A that is granted the Full Access permission to User B’s mailbox cannot see detailed free/busy information for User B in an Exchange Server 2010 environment
2701624 ItemSubject field is empty when you run the Search-MailboxAuditLog cmdlet together with the ShowDetails parameter in an Exchange Server 2010 environment
2702963 The "Open Message In Conflict" button is not available in the conflict notification message in Exchange Server 2010
2707242 The Exchange Information Store service stops responding on an Exchange Server 2010 server
2709014 EdgeTransport.exe process crashes intermittently on an Exchange Server 2010 server
2709935 EdgeTransport.exe process repeatedly crashes on an Exchange Server 2010 server
2713339 Multi-Mailbox Search feature returns incorrect results when you perform a complex discovery search in an Exchange Server 2010 environment
2713371 Throttling policy throttles all EWS applications in Exchange Server 2010
2719894 The Microsoft Exchange RPC Client Access service consumes 100 percent of CPU resources and stops responding on an Exchange Server 2010 Client Access server
2723383 Incorrect time zone in a notification when the Resource Booking Attendant declines a meeting request from a user in a different time zone in an Exchange Server 2010 environment
2724188 A subject that contains colons is truncated in a mixed Exchange Server 2003 and Exchange Server 2010 environment
726897 Event 14035 or Event 1006 is logged when Admin sessions are exhausted in an Exchange Server 2010 environment
Update Rollup 4 for Exchange Server 2010 SP2 also resolves the issue that is described in Microsoft Security Bulletin MS12-058.
For more information about Security Bulletin MS12-058, click the following article number to view the article in the Microsoft Knowledge Base:
2740358 MS12-058: Vulnerability in Microsoft Exchange Server WebReady document viewing could allow remote code execution: August 14, 2012