@grumpybozo : I definitely am not angry with you (I very much agree).
Unfortunately many admins treat security solutions like they're a religion.
Some time age there was a hefty debate on a Dutch "mostly admins" site (https://tweakers.net, I'd have to look up the exact thread) about the "correct" sending and receiving MTA configurations. There was no agreement.
Microsoft even used to ignore SPF/DKIM/DMARC if the sender was in the "safe senders" list (which the user's address book defaults to). What could possibly go wrong (later MS corrected that).
The screenshot below is from part of https://www.security.nl/posting/766069/DMARC+bypass+%28Outlook+only%3F%29#posting767981 (I wrote that Sept. 14, 2022).
Edited 23:36 UTC to add: {
https://arxiv.org/abs/2302.07287
Forward Pass: On the Security Implications of Email Forwarding Mechanism and Policy
Enze Liu, Gautam Akiwate, Mattijs Jonker, Ariana Mirian, Grant Ho, Geoffrey M. Voelker, Stefan Savage
}