Hi Thames,

 

Exchange ActiveSync will only work on mobile devices, tablets and Outlook 2013. To use an Exchange account with Mac Mail, you'll actually need Exchange Web Services. When you have EWS enabled, you can follow these steps to configure it with Mac Mail: Configure Apple Mail for Exchange Web Services. If you don't already have EWS and would like to try it out before purchasing, you can do so by following these steps: Activate a Free Trial for Microsoft Exchange Web Services. 

 

Alternatively, you can use IMAP with Mac Mail as well. This isn't the recommended method, as it doesn't use push technology to deliver to the client in real time, but it does include a two-way sync of all mail folders. More info on this can be found here: Set up Mac Mail with IMAP.

 

I hope this helps!