One way people have been getting client-side Exchange Server ActiveSync (EAS) from devices which don’t supply logging export capabilities is to have the phone sync through a wireless router attached to a PC which fiddler taking traces.  This is very helpful since getting logs otherwise and is usually the only way to get a full EAS trace. Fiddler works great for SSL decoding Exchange 365 content since it acts as a type of proxy. 

The problem with using Fiddler is that EAS traffic is WBXML encoded (i.e. its a blob).  The Exchange Server Interoperability Guidance documents have some really good sample code which can help if used in a Fiddler Inspector application.  So, I leverage the guidance samples to build Inspector which will show the WBXML traffic in XML format which is a lot easier to read than pure WBXML.

EAS Inspector for Fiddler
https://easinspectorforfiddler.codeplex.com/

Be sure to read the notes in the project prior to compiling.