21 Sep
2017
21 Sep
'17
9:04 a.m.
On Wed, 20 Sep 2017, Grant Taylor wrote:
On 09/20/2017 07:30 PM, Lawrence Stewart wrote:
This is a well established technique known as Nolisting. I believe the
safest option is for the port to be unbound and thus for a TCP RST to be
sent.
en.wikipedia.org/wiki/Nolisting
Rob
We have 3 MX records with weights 10 50 100, but
only the second one has an
SMTP server behind it. This tends to discourage spammers.
Do the first and third MX actually resolve to an IP? Are they pingable?
Are you sending TCP resets?