User has just started to complain that his mail app is not connecting to exchange when connected to the remote office wifi.

Has previously been working fine to my knowledge. Doesn't anyone know of any changes to IOS 9.x (prob SSL likely as we do use a self signed cert) that might have caused this to stop working?

We have a central office with a Windows 2008 R2 DC and two branch offices connected via Cisco IPSEC VPN. The DC also does DNS for both branch offices and has been up and running for several years without issue. Exchange 2010 is hosted at the central site and users log onto the DC access Exchnage via Outlook from both remote offices.

I understand that as the central office has ssl and smtp port forwarded that both of these services are inaccessible via the VPN but to my knowledge iPhone activesync clients have not had any issue connecting previously.

Thinking I need a sanity check.