iPhone and Outlook for Mac Sync

Hello, I am using an iPhone 6 iOS 8.3 and Mac with Outlook for Mac 2011 (14.51). I am having some syncing issues between the two devices using Exchange server. When I read or delete an email on my iPhone it syncs fine with the Outlook for Mac. Also, when I read an email on my Mac, it is marked as read on my iPhone which is great. However, when I delete the email on my Mac it still remains on my iPhone as unread and doesn't delete. Any suggestions?