Enterprise Activation Service with AT&T

I'm new to the forum and have done some initial searches on this topic but couldn't find anything but pardon me if it has been answered before :

I host my own BES Express and I have the Enterprise Activation feature added to my Business account with AT&T Wireless. I have been paying a monthly fee for this feature for almost 2 years now. I have since activated 2 Blackberrys wirelessly since having this service.

I'm trying to cut costs in this recession, can someone tell me if I need to keep paying this monthly fee if I have no intention of 'Activating' anymore Blackberries on this account for another year?

Does this additional feature facilitate activations only? Or if I remove it from my account, I will no longer be able to send & receive emails from my BES Express?

Any tried and tested answers on this would be greatly appreciated.

thanks