Reject mail from invalid domains

[Koopmann, Jan-Peter]

On Monday, May 28, 2007 6:16 PM Jorge Costinha wrote: 


>       im using Fedora core 6, with Mailscanner 4.59.4 and sendmail
> 8.13.8. I want to block email from invalid domains. Can i do this with
> Mailscanner/spamassassin or has to be done at MTA level?

You probably could do this with spamassassin but the MTA is the correct
place. How do you define "invalid domain"? That's the interesting
question. 

Regards,
  JP