On Mon, 2007-03-12 at 12:00 -0400, Marcelo Maraboli wrote: > > I agree..... callbacks are not enough, you can reach a > false conclusion, that´s why I use SPF along with callbacks... > > on the same message, my MX concludes: > > "you are sending email "from [EMAIL PROTECTED]", but shire.net > says YOUR IP address is not allowed to send email on behalf > of that domain, therefore YOU ARE FAKE/FORGED" ..---> reject > > regards, >
I'm not sure what you mean by callbacks but if that involves talking to mx.example.com and trying to figure out if [EMAIL PROTECTED] is a valid address go ahead. I would consider a mailserver that answers that question a security risk as it is freely giving away information about your domain without notifying you. For a long time my mx servers would answer any such question in the affirmative regardless of whether or not the mail account existed. As the above poster says SPF is the way to go. SPF gives the receiving MTA a mechanism to vet inbound mail. For any combination of <mail server> and <from address/from domain> there are three possible results from an SPF check: The server is allowed to send mail for the domain; The server is not allowed to send mail for the domain; And I cannot tell because the owner of the domain hasn't published an SPF record. The only problem with SPF is that it's not more widely implemented so the third response is sadly more common than the first two. -- Chris _______________________________________________ firstname.lastname@example.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"