James B. Byrne:
> Without going into a lot of detail and without naming names I wish to know if,
> at the time of connection to Postfix, there exists any feasible means of
> determining the registrar used by the connecting domain? As well, I would
Beware, some whois servers enforce rate limits, so this is likely
to cause problems for a busy mail server.
On the other hand, Postfix has support to block domains by their
DNS (or MX) service provider: check_mumble_{ns,mx}_access for mumble
in client, reverse_client, helo, sender, recipient.
I have used that in the past to block snowshoe spam.
Wietse
