Sun Protection Factor? That’s what most of us think of, but I’ve been experimenting with SPF – Sender Policy Framework. For more, visit: http://www.openspf.org/
I send e-mail from various web applications I maintain so I did not want to make my life hard. So… I took the easy way and left the defaults as they were.
Here is a simple example: “v=spf1 a mx ?all” This is a permissive setting as it lets any questionable mail through because of the ?all. I changed mine to read -all on the end which means “if in doubt, deny”.
I’ve not included my real setting here in case there is some critical flaw, I don’t want people to know that it’s set to. However, I did tighten it up. That had some clear down sides. I had a TFS (Team Foundation Server) in a virtual PC that would send e-mail to me when the builds would fail. That’s now broken. But I hope this will reduce the amount of spoof mail (in my mind far worse than spam) that I receive. It will take some time to tell whether it works or not… I’ll update this post when I know more about the results.