NOD32 Ent. & Small Business Server

I am purchasing NOD32 for a non-profit organization that uses Small Business Server. Because they have 30 computers the reseller told me that they can not use the Small Business Bundle because it is limited to 26 seats so I purchased the Enterprise version for them. When I went to download the software I discovered that it did not include NOD32 for Exchange Server. When I asked him about it he told me that I did not need it since it scans .pst files.

As far as I know there are no .pst files on Exchage server so how are they going to be protected without XMON?