Is it possible to reject if the sender domain's MX record equals an illegal value? Such as domains that have an MX hostname of "localhost" or an MX hostname which resolves to a bogus IP.
For example check out the MX for "4md401.com". Its MX hostname is mail.4md401.com, which resolves to 127.0.0.1 I've seen similar cases where the MX resolves to 0.0.0.0 or a private IP. I've also seen where there is no MX record but the domain's A record resolves to a bogus IP. I'd like to be able to block all of these. Is it possible? Bill
