Thanks for your inquiry. Please let me know if you continue to have difficulties with the syncing of emails on your client. EWS is only available for Mac Mail and Outlook 2011. The EAS is available for ActiveSync clients such as Outlook 2013 with an SSL certificate and mobile devices other than Apple iphone.
How long is the delay of emails being delivered to the email client apposed to the mobile devices ? Please let us know if you have submitted a Support Ticket on this issue. We may be able to review the process in more depth once we reviewed the Delivery logs and EWS entries.
If there is any issue or bug detected with the application or protocol we will then provide a credit on the Support ticket.