I have a strange issue with iPhone (3G) account for one of my users.
When he configures his exchange account it's being saved correctly but when he tries to read email it says that there was no connection to the server and even his folder tree is not being retreived. I have about 50 other users that work just fine.
Also an account of a different user works just fine of his iPhone.
His iPhone language is French but I have other French users that work just fine and changing the interface to English did not solve the problem.
Also, OMS access works fine for him with his user.