Which version of Outlook you are running? Only Outlook 2013 and above can only be used with ActiveSync and if you are on Outlook 2011 and below, you will need to activate EWS for your SmarterMail install.
Authorized SmarterTools Reseller. Ask Us For Your 10% SmarterTools License Purchase for entire Jan 2015.
http:///www.tweakservers.com