Microsoft Exchange Server addresses have two parts: an address type and the address itself. EX is the address type for native Microsoft Exchange Server addresses. The unique address for each object in the Microsoft Exchange Server directory is the object’s distinguished name (DN). The DN starts with the Microsoft Exchange Server organization at the highest level and continues to the object being named. For example, the DN for John Jones might be:
/o=Trager/ou=New York/cn=Recipients/cn=JohnJ
corresponding to a Microsoft Exchange Server address of:
EX:/o=Trager/ou=New York/cn=Recipients/cn=JohnJ