Here's an interesting one.
We have Lync 2013 with an edge and two FE servers.
We have an issue with the Lync 2013 iPhone client connecting to EWS.
The cause is that we are currently upgrading to Exchange 2013 from Exchange 2007. Exchange 2013 is running the show for EWS via our autodiscover. Which it needs to, presumably, or the migrated users wont work properly.
The issue is that for those users still on Exchange 2007, which is most of them for quite a while until we have run a PoC, the EWS provided in 2013 negotiates the new SOAP based connection. Then it fails as this doesn't work for Exchange 2007.
It seems to me, short of attaching an EX 2007 EWS to the long list of URLs the mobile client attempts after failing on the autodiscover revealed EWS, is to force the old POX method on Exchange 2013 - at least until we have migrated all of the mailboxes.
So, my question, how do I do that! Google has drawn a blank!