yes, it's pretty stupid but it's the product that the commercial team sells (your own small managed private mail server). Some of the servers have more than 2000 accounts but others have 6 or 10... A few years ago, until 2006, the servers where small appliances installed on the client's office. Now they work the same way but mostly virtual and since most of the clients are small bussiness.. some have really few accounts.

On our shared mail system we have about 40k accounts in 2 cyrus servers (with 2 more for HA)