>> Thanks for the reply. Is there a way to query DNS if the specified MX is >> present so I do not have to maintain the list of allowed domains? > > I send lots of spam, and I configure DNS such that the sender domain > of my spam resolves to your MX (*). Would you please receive millions > non-deliverable mail notifications for me?
Yes. I was looking for a very short term (1-2 hours) fix for the problem. I decided to go for a better approach and have the list of allowed domains generated automatically so there is basic protection against the semi-openrelay described above. > > Thanks for helping out. > > Wietse > > (*) I'll be happy to provide a bogus primary MX address that never > responds. BR Christoph
