In one for the nerdy mail system administrators out there, I spotted a rather uncommon SPF result in my SMTP logs this morning.
If you know your SPF, you’ll know that no matter what IP address a piece of email comes from, with these records, the email will ALWAYS pass an SPF lookup. Clearly an interesting spammer tactic, and a demonstration as to why SPF is far from perfect, given you can put anything you like in the records.
I’ve discussed SPF before, and while it is certainly useful, what I saw this morning demonstrates that a better approach is needed.