Hi Juerg,

I've run a little test whether Swiss ISPs use SPF or not and it turned out that very few have actually implemented it (actually, I found not a single one). Is there a reason for that? It's a very simple implementation and it could prevent a lot of damage like the most recent one after Sober.Q.

We do, too. We offered our customers to implement SPF for their domains and some did, and most new customers have SPF too. People do not like spam or viruses being sent out with their address as sender so they were quite happy to hear about SPF (although it's sometimes hard to explain that SPF does not prevent these mails from being SENT...).

Most customers are using SMTP AUTH and we're also offering port 587 in case port 25 is blocked.

We are also filtering on SPF. It's not helping a LOT but it still is. And it's also filtering viruses.

So in my experience SPF is a good thing, but I suppose implementing SPF in larger companies than ours can be quite difficult.

Daniel

BTW: Hostpoint has SPF records for all customers, although it's just "v=spf1 mx ?all" and thus quite useless.