SPF-enabled spam domains
Among the many anti-spam measures on my mail server – which help me reject 5000 spam attempts per day – is SPF. SPF allows domain name owners to specify which mail servers are allowed to send its mail. That makes it an excellent way to detect address forgeries, a favorite spammer tool.
One of the early questions raised about SPF was: won’t spammers just buy their own domains and set up their own SPF records that say it’s all OK? You can read the answer in the SPF FAQ, but the short version is: Yes, they will, but it won’t give them a free pass.