[qmailadmin] Receive messages from ONE domain.

[Jason King]

I have ONE account on my qmail server that needs to be able to receive 
mail from only one domain, namely its own domain. Users will forward 
incorrectly labled spam/ham to this folder for spamassassin to learn 
through a script. But I don't want that account open for everyone in the 
world to send to it...because then anyone could send anything into that 
box and when spamassassin would go through the learning process it would 
begin to skew the database. Only valid emails from my own domain should 
be able to send anything to this box. Does anyone know if there is a way 
to accomplish this?