Hallo,
hier ein kleiner Auszug aus der Admin-Hilfe (hier engl.)
Inbound recipient lookups are controlled by the Address lookup setting on the Router/SMTP - Basics tab of the Configuration Settings document. This setting determines the criteria that the Router uses when attempting to match the SMTP address on an incoming message to an entry in the $Users view. The Router matches addresses based on:
The full SMTP address only -- for example, Genevieve_Martin@acme.com
The local part of the SMTP address (that is, the part to the left of the @ sign) only -- for example, Genevieve_Martin
The full SMTP address, and then if no match is found, the local part address
When using full name matching, the Router searches the Domino Directory for an exact match of the entire SMTP address (for example, First_Last@Acme.com). If an exact match is not found, the Router performs a secondary search if the domain suffix of the incoming address is listed in the Global domain document as an Internet domain alias. For this secondary search, the Router replaces the given domain suffix with the domain suffix designated in the Global domain document as the Primary domain name.