[TUHS] Who is running their own mail server and what do you run?

[Robert Brockway]

On Wed, 20 Sep 2017, Grant Taylor wrote:

> On 09/20/2017 07:30 PM, Lawrence Stewart wrote:
>> 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?

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