Types of licenses and their distinction

There are various types of licenses for different numbers of mailboxes and server licenses: the License on SBS is for SBS Server; the License on Exchange Server is for Exchange Standard Edition; and the License on Exchange Server Enterprise is for Exchange Server Enterprise Edition. If you use a Windows Essential Business (WEB) server, then you will need to obtain a license for Exchange Server Standard.

Licenses on N mailboxes restrict the quantity of POP3 user accounts to N and do not allow use of global (catch-all) mailboxes. This type of license will suit you if you do not need that option.

If the possibility to use global (Catch-all) mailboxes is necessary, then you need to acquire one of server licenses. The quantity of mailboxes for server licenses is unlimited.