Samsung s4 sync calender but not mail

Hello there.

The problem: after upgrading our data synchronizer to version 1.2.5 Build: 299, one employee have not been able to get his emails synced to his Samsung galaxy S4.
The strange part is that the calender gets synced perfectly. Another employee with the exact same phone and android version got i working with both mail and calender.
After troubleshooting and testing, iv'e come to the conclusion that it is not the phone that seems to be the problem. I'd try to sync another groupwise account on the phone and it worked perfectly.
So i think that the problem is within the groupwise account.
Also have I tried a structural rebuild on the groupwise account, but with no luck.

Any ideas or advices to troubleshooting this further?

We use groupwise 8.0.

Thanks in advance