Exchange Server 2013 SP1 is a service pack for Exchange Server 2013 that includes a number of new and updated Exchange Server 2013 features and capabilities.
Released in February 2014, notable Exchange Server 2013 SP1 features include:
- Support for Windows Server 2012 R2
- Data Loss Prevention (DLP) improvements
- S/MIME> encryption for Outlook Web App (OWA)
- Edge transport server role
- Active Directory Federation Services (ADFS) for OWA
Before upgrading and deploying Exchange Server 2013 SP1, Microsoft recommends updating Active Directory. If using SP1 is the first Exchange 2013 deployment in the organization, Microsoft says to include the client access server role as well as the mailbox server role.