Since upgrading to the CU6 release of Exchange 2013, ActiveSync has been broken in some ways. We are running a fully native Exchange 2013 setup, with just one Exchange 2013 Standard Server, on Win 2012.
The few instances of ActiveSync still working are for profiles already configured on devices BEFORE CU6 was installed (in our case, all devices are running Apple iOS 7.1.2). Any profiles added to iOS after the CU6 will not work (apart from a brief window when it did), presenting the error on device:
"Cannot Get Mail
The connection to the server failed"
I've run connectivity tests too, which at times have indicated different things, most commonly problems along the lines of http error 500 for Autodiscovery. But these have varied, and once (for a brief period) new Activesync configurations started working again. I've checked my host records on DNS, and have even reset the IIS parts of Exchange 2013 to defaults, but to no avail.
I'm aware Microsoft have screwed up a bit with CU6 - I'm also aware of the co-existence with Exchange 2007 error causing ActiveSync problems. We don't have any such setup, but perhaps the issues are more widespread and somewhat related. I am going to try and speak to Microsoft about it - we are nearing the end of 180 day trial, and it would be nice to have this sorted before I go ahead and buy it.
I've also considered setting up another trial of Exchange 2013 CU4 and trying to migrate all mailboxes back to this, but I'm not sure whether that will actually be viable.
Any thoughts appreciated - I wished I'd stayed at CU4, as the CU6 update was only installed to try and correct another problem it didn't even fix!!
Any input gratefully received.