Hello I made a mistake I didn't check the Mailbox Role during the installation so I just installed the 1st Exchange Server 2013 SP1 into my organization with the CAS Server Role can I add the Mailbox Server Role after doing this? Or do I have to decommission this server to start a new installation within a Multi role Server (Mailbox/CAS)???? 

Thanks for the Help

• Edited by Crismart Friday, February 13, 2015 5:40 AM

https://technet.microsoft.com/en-us/library/bb124778(v=exchg.150).aspx

After you install any server roles on a computer running Exchange 2013, you can't use the Exchange 2013 Setup wizard to add any additional server roles to this computer. If you want to add more server roles to a computer, you must either use Add or Remove Programs from Control Panel or use Setup.exe from a Command Prompt window.

Hi,

As what Andy suggested above, you can't add additional server role after you install any server roles on a computer running Exchange 2013.

Best regards,