Microsoft has released Update Rollup 5 for Exchange Server 2010 Service Pack 1 (KB2582113)

Update Rollup 5 for Exchange Server 2010 Service Pack 1 resolves issues that were found in Exchange Server 2010 Service Pack 1 since the software was released. This update rollup is highly recommended for all Exchange Server 2010 Service Pack 1 customers.

Issues that the update rollup resolves

Update Rollup 5 for Exchange Server 2010 SP1 resolves the issues that are described in the following Microsoft Knowledge Base articles:
2275156 The inline contents disposition is removed when you send a "Content-Disposition: inline" email message by using EWS in an Exchange Server 2010 environment
2499044 You cannot save attachments in an email message by using OWA if the subject line contains special characters in an Exchange Server 2010 environment
2509306 Journal reports are expired or lost when the Microsoft Exchange Transport service is restarted in an Exchange Server 2010 environment
2514766 A RBAC role assignee can unexpectedly run the Add-ADPermission command on an Exchange Server 2010 server that is outside the role assignment scope
2529715 Slow network or replication issues after you change the number of virus scanning API threads in Microsoft Exchange Server 2010
2536704 Mailbox users who are migrated by using ILM 2007 cannot use the Options menu in OWA in an Exchange Server 2010 environment
2537094 French translation errors occur when you edit a response to a meeting request by using OWA in an Exchange Server 2010 SP1 environment
2554604 A RBAC role assignee can unexpectedly manage certificates that are outside the role assignment scope in an Exchange Server 2010 environment
2555800 You cannot use the GetItem operation in EWS to retrieve properties of an email message in an Exchange Server 2010 environment
2555850 You cannot delete a mailbox folder that starts with a special character in its name by using Outlook in an Exchange Server 2010 environment
2556096 The columns in the .csv logging file are not lined up correctly when you perform a discovery search on a mailbox in an Exchange Server 2010 environment
2556107 The columns in the .csv logging file are not lined up correctly when you perform a discovery search on a mailbox in an Exchange Server 2010 environment
2556133 A device that uses Exchange ActiveSync cannot access mailboxes in an Exchange Server 2010 environment
2556156 Extra.exe crashes when it performs RPC activity checks against an Exchange Server 2010 server
2556352 "ChangeKey is required for this operation" error message in Outlook for Mac 2011 in an Exchange Server 2010 environment
2556407 Certain client-only message rules do not take effect on email messages that are saved as drafts in an Exchange Server 2010 environment
2559926 "There are no items to show in this view." error message when you try to view a folder by using Outlook in an Exchange Server 2010 environment
2572958 The "Test-OutlookConnectivity -Protocol HTTP" command fails with an HTTP 401 error in an Exchange Server 2010 environment

  Update Rollup 5 for Exchange Server 2010 Service Pack 1 (KB2582113)