Activesync publication.

I have a problem with publishing Activesync. I made an OWA publication and it works. When I select the Activesync publishing option, the client device does not connect. I watch the traffic and see that there are packets from the client from the client on the WAN interface, FortiWEB responds to the client. But there are no packages on the LAN interface to Exchange and the connection does not work. Are there any special instructions for setting up Activesync publishing? Maybe there is a cookbook for Activesync the same as for OWA?