Hi all,
Got a user who discovered mail from outsice the lnd couldn’t receive any email.
Took a lot off time to find out that he has the “wrong” lastname ;-(
The email address in question: Surename.Kor@Domain.com
When sending to this specific email address Domino sends (in our case) this email
to another external server in the notesnetwork as follows:
Surename@kor
In the end (took some time to go around the world) I got a error message from a server
Korea 
You cn try it yourself bij adding an alias in the NAB.