I've been having a number of emails recently from Yahoo and AOL senders
hitting the RCVD_NUMERIC_HELO rule. I'm trying to understand what is
going on:
1. First off, the rule hits on the EHLO line - which means the it is an
authenticated SMTP submission. Is the correct HELO format important when
the client actually does authenticated SMTP? After all, if it is EHLO,
it probably is an MUA, which can't be expected to have proper DNS etc.
2. Or maybe this is caused by Yahoo's end - in which case would some
sort of exception be a good idea?
Or maybe I am misunderstanding completely what is going on? I've
uploaded a set of headers here: https://pastebin.com/KDV1f0wW
Thank you for any useful hints.
