Basically as the title says; 7100 can't send emails but it receives them fine. Also changes made in calendar and contacts appear fine.
his is only an issue with one user, everyone else work perfectly.
Could this be an issue with the SIM? (To be honest I can't see why it would be, but I'm running out of options)
Or could it be the device? I've heard a few people complain about the 7100 and issues they've had with it and I was just wondering if this was one of them.

Thanks.

Is it BES? If so, try resending service books.

yes it's a BES.
Seems like that will be a good idea.
I forget how many Service Books are installed by default? Is it 10?
I've got 11 on mine but that would be because I've started to POP my G-Mail right?

Cheers.

Possibly. CMIME is the one that deals with email though I believe.