On 2017-03-09 13:41, Noel Jones wrote:
On 3/9/2017 3:16 PM, MRob wrote:
obtained by HELO? Is there something in the tcp connection that
identifies the hostname? Sorry if I misunderstood this part.
The HELO name is not related to and doesn't matter for
reject_unknown_client_hostname. Perhaps you were confused by the
different context of hostname; client (rDNS) vs. HELO (SMTP).
The client hostname is determined by an rDNS lookup of the
connecting IP. The resulting rDNS hostname is then looked up, and
must resolve to the connecting IP. This is also referred to as
Forward Confirmed reverse DNS.
So is there any restriction that compares the client IP mapping with the
HELO hostname? Is that a bad idea?
