The odd thing is that on the same device I can connect to one Exchange mailbox but not to another.
Obviously there is something with that one account. I checked its AD properties and the security setting has the "Allow inheritable permissions from the parent ..." box checked.
In the past, putting a check in that box when it was not checked fixed the problem. I also unchecked it and checked it again but this time no joy.
So it's not a problem with the device or the Exchange server.
I successfully moved the mailbox to another database and the mailbox had no corrupt messages.
This user was using a iPhone 3 before and had no problems.
His OWA options page shows no connected mobile devices.
Maybe in the process of wiping his iPhone 3 device something happened?
He's on an iPhone 4 but I'm testing it on my iPad so the device itself is not an issue.
So on my iPad I configured my mailbox and then added his but my mailbox works but not his.
I also reset his AD password but it didn't help.
Thanks for your help.
WC