On 4/2/22 3:23 PM, Jeroen Massar via NANOG wrote:
Hi Dan,
Hope the rest of the world is treating you decently!
There are a lot of bits and bobs that one has to get right for mail to flow,
amongst which:
- IP -> PTR lookup -> that hostname lookup, and match to IP again
(https://en.wikipedia.org/wiki/Forward-confirmed_reverse_DNS)
- SPF
- DKIM
- DMARC
- ARC (for mailinglists)
Seriously spend zero time on ARC. It doesn't work as advertised and is basically snake oil.
Mike
