Today the Exchange Team released RU6 for Exchange Server 2010 Service Pack 1 (KB2608646). This update raises Exchange 2010 version number to 14.1.355.2.

Here’s the list of changes included in this rollup:

• 2431609  An update is available that updates the message of a retention policy in OWA for Exchange Server 2010
• 2449266  EWS drops the TCP connection to the EWS client application without any error message in a Microsoft Exchange Server 2010 environment
• 2480474  A Users do not receive quota warning messages after applying SP1 for Exchange 2010
• 2514820  An incoming fax message is not delivered to the recipient in an Exchange Server 2010 SP1 environment
• 2521927  Disabling the Exchange ActiveSync Integration feature for OWA does not take effect in OWA Premium clients in an Exchange Server 2010 environment
• 2528854  The Microsoft Exchange Mailbox Replication service crashes on a computer that has Exchange Server 2010 SP1 installed
• 2535289  The Microsoft Exchange Information Store service crashes occasionally when you run an antivirus application on an Exchange Server 2010 Mailbox server
• 2536313  Slow message delivery and mailbox access for journaling mailboxes on an Exchange Server 2010 server
• 2544246  You receive a NRN of a meeting request 120 days later after the recipient accepted the request in an Exchange Server 2010 SP1 environment
• 2548246  The Microsoft Exchange Information Store service crashes occasionally when a folder view is corrupted on an Exchange Server 2010 mailbox server
• 2549183  “There are no objects to select” message when you try to use the EMC to specify a server to connect to in an Exchange Server 2010 SP1 environment
• 2549289  A RBAC role assignee can unexpectedly run the Add-MailboxPermission command or the Remove-MailboxPermission command on an Exchange Server 2010 server that is outside the role assignment scope
• 2555851  A mailbox does not appear in certain address lists after you run commands on the mailbox in an Exchange Server 2010 SP1 environment
• 2559814  A user cannot add or remove delegates from a mailbox by using Outlook in an Exchange Server 2010 environment
• 2561514  Exchange Server 2003 user cannot view the free/busy information of a user in a different federated organization
• 2563860  You cannot create a new mailbox database if you already have 1000 mailbox databases in an Exchange Server 2010 environment
• 2567409  Certain free/busy messages are not replicated from an Exchange Server 2010 server to an Exchange Server 2003 server
• 2571791  Retention policies are applied to Contact items unexpectedly in an Exchange Server 2010 environment
• 2572052  Certain properties of a recurring meeting request from external email accounts are missing in an Exchange Server 2010 SP1 environment
• 2575005  You cannot start the EMC or the EMS in an Exchange Server 2010 Service Pack 1 environment
• 2578631  Certain users cannot send email messages to a mail-enabled public folder in an Exchange Server 2010 environment
• 2579172  Items that are deleted or moved still appear in the original folder when you use Office Outlook in online mode to access an Exchange Server 2010 mailbox
• 2579671  No results returned when you use the ExpandGroup method in EWS to retrieve a list of members of a Dynamic Distribution Group in an Exchange Server 2010 environment
• 2582095  The SmtpMaxMessagesPerConnection property of a send connector is not replicated to the subscribed Edge Transport server in an Exchange Server 2010 environment
• 2600835  The RPC Client Access service crashes when you delete an attachment of an item by using Outlook in online mode in an Exchange Server 2010 SP1 environment
• 2601701  The memory usage of the MSExchangeRepl.exe process keeps increasing when you perform a VSS backup on Exchange Server 2010 databases
• 2616127  “0x80041606” error code when you use Outlook in online mode to search for a keyword against a mailbox in an Exchange Server 2010 environment
• 2617126  The Store.exe process crashes when you send an email message that has attachments in an Exchange Server 2010 SP1 environment
• 2627769  Some time zones in OWA are not synchronized with Windows in an Exchange Server 2010 environment

Note that update rollups are cumulative, i.e. they contain fixes released in earlier update rollups for the same product level (RTM, SPx). This means you don’t need to install previous update rollups during a fresh installation but can start with the latest rollup available right away.

I’d recommend to thoroughly test this rollup in a test and acceptance environment first, prior to implementing it in production.

Note that when running ForeFront Protection for Exchange, you need to stop all ForeFront services before installing the rollup. While not entirely perfect, this is a welcome improvement over earlier rollups, where you had to disable and re-enable ForeFront using fcsutility /disable and fcsutility /enable respectively.

For the correct procedure on how to update a DAG and its members, check here.

You can download Exchange 2010 SP1 Rollup 6 here.