The long awaited Service Pack 1 for Exchange Server 2013 was released today by the Exchange Team (KB2926248). This update raises Exchange 2013 version number to 15.0.847.32.

Service Pack 1 introduces the following changes or enhancements:

• Support for running Exchange Server 2013 SP1 on Windows Server 2012 R2.
• Support for Windows Server 2012 R2 Domain Controllers and Windows Server 2012 R2 Forest and Domain Functional Level.
• MAPI over HTTP.  More information on MAPI over HTTP here. Note that MAPI over HTTP requires Outlook 2013 SP1; you can download Office 2013 SP1 32-bit version here and the 64-bit version here.
• DLP policy tips for OWA.
• Add custom document types to DLP using fingerprinting technologies.
• Cmdlet logging in Exchange Administrative Console.
• Support for IP-less DAGs (on Windows Server 2012 R2).
• S/MIME support.
• Rich-Text editor for OWA.
• Edge Transport server role.
• Support for SSL Offloading.

Service Pack 1 includes the following fixes:

• 2860242 HTML format is lost after saving as an MSG file in Exchange 2013
• 2900076 Mailbox quota warning message uses an incorrect language in Exchange Server 2013
• 2910199 “Reply all by IM” chat window displays seven recipients in Outlook Web App
• 2913999 Meeting request body and instructions are lost in delegate’s auto-forwarded meeting request
• 2918655 Microsoft.Exchange.Servicehost.exe crashes after you enable FIPS
• 2918951 Users cannot access public folders after you upgrade to Exchange Server 2013 Cumulative Update 3
• 2925281 Outlook connectivity issue if SSLOffloading is “True” in Exchange 2013
• 2925544 Empty ExternalURL value for ActiveSync virtual directory after build-to-build upgrade of Exchange Server 2013
• 2927708 Resource mailboxes that are created by EAC will not be updated by policies in Exchange Server 2013
• 2928748 Default from delegate’s address in shared mailboxes in Exchange Server 2013
• 2928803 Long server connection for Outlook after a database failover in Exchange Server 2013
• 2930346 POP3 access does not work if the name of the resource mailbox differs from the user’s name
• 2930348 Manual redirection occurs in Outlook Web App if External URLs in each site are the same
• 2930352 Outlook Web App cross-site silent redirection does not work in Exchange Server 2013

Cumulative Updates and Service Packs includes schema and AD changes, so make sure you run PrepareSchema /PrepareAD. After updating, the schema version will be 15292.

Note that Service Packs and Cumulative Updates can be installed directly, i.e. no need to install RTM prior to Cumulative Updates or Service Packs. Note that once applied, you can’t uninstall a Cumulative Update or Service Pack nor any of the installed Exchange server roles. The order of upgrading servers is irrelevant, unlike with previous Exchange generations.

Finally, and I can’t emphasize this enough: For any Hotfix, Rollup, Service Pack or Cumulative Update, I’d recommend to thoroughly test this in a test and acceptance environment first, prior to implementing it in production. When you lack such facilities, hold out a week or two and monitor the comments on the release article or TechNet forum for any issues.

Also check with any 3rd party products you may use – there are reports of compatibility issues with 3rd party transport agents by Exclaimer, Trendmicro (other AV solutions possibly as well) and CodeTwo. The cause of the Transport service failing to start or problems with installing 3rd party transport agents has been identified. A workaround can be found here.

You can download Exchange 2013 Service Pack 1 here. The Exchange 2013 SP1 UM Language Packs can be found here. More details about these changes, preparing Active Directory or installing this Cumulative Update can be found in the original announcement here.