freitasm:
When you have a perfectly configured SPF/DKIM/DMARC set that works everywhere - except at the Commerce Commission which uses a third party spam filter that then forwards the email to their final recipients, at which point SPF fails and the message bounces because the sender IP is no longer one of the IPs I have in the SPF record but the IP for their (badly configured) anti-spam service.
And you can't even email them to let them know.
We have had this issue a number of times with clients recently. Pretty much anytime you create a auto-forward to an email. Very annoying.