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Originally posted by Vatoloco
I have the same question. The http://spf.pobox.com/ site was suggested by dnsreport.com.
Do you have to create this record for every single site you host on your server?
Actually, SPF will work best when there is a record for every domain that isn't a spammer(humor unintentional).
A good idea would be to provide a howto to your customers, or some script, so they can run it themselves, if they want to. But a SPF can't help prevent what anti-uce advocates call joe jobs, without a SPF record existing for that domain, so joe jobs are possible until you get each domain/parked domain/addon domain protected.
I hope this helps.