Half-Grey-Listing (Update 02)

Posted on June 28, 2017 by Hendrik Jäger

Half-Grey Listing

Concepts of nolisting and greylisting should be known.

Imagine this setup:

example.org         IN  MX  05 192.0.2.5
example.org         IN  MX  50 192.0.2.50
example.org         IN  MX  99 192.0.2.99

All addresses are on the same host running exim. Exim would go through the whole process (almost – since most stuff is rejected anyway, one may want to optimize here) as normal, but will tempreject (almost – abuse@ and postmaster@ should probably be unfiltered, just to make sure) everything on 192.0.2.5 and 192.0.2.99.

Is anything wrong about this (WRT to RFCs)? What might go wrong?

UPDATE 01

It seems there are a few appliances that can’t properly deal with this setup:

I contacted all of them and the feedback I got so far:

I disabled the setup for now, though, too many broken sites out there …

UPDATE 02

Setup running on the mostly unused domain hj-systems.de.

You can send me a testmail to test@hj-systems.de to see whether your email-infrastructure is able to deliver it.

If you have trouble getting the mails out, send to postmaster@hj-systems.de, which should always be deliverable.