We have a couple of users in our organisation who are unable to sync any emails older than a day. The users need to be syncing at least a week. If they set "mail days to sync" to 3 days or more, the iPhone email app gives the following error when syncing:
Cannot get mail - the connection to the server failed.
We are using Exchange 2003 SP2 but have tested on multiple iPhones (4, 5 and 6, all up-to-date). OWA/OMA is working fine, their email accounts sync on Android mobiles, but everybody else in the company is able to access emails on iPhones.
Any input will be greatly appreciated.