Hi Axel,
ich nehme an du meinst die generelle Weiterleitung.
Das sagt die Hilfe:
A forwarding address allows users who have Person documents in the Domino Directory to have their mail forwarded to another address. There are various reasons why this is useful:
1. Users change their names -- for example, because of marriage -- but still wants to receive all their messages.
2. User move -- for example, a user may resign from the company but leave a forwarding address so that mail addressed to the old address is forwarded to the new location.
3. Users use a different mail system and do not have Notes mail files.
Es gibt dort keine Unterteilung nach intern oder extern.

MOD
P.S. Ansonsten nimm den Tip von majonese