Re: [exim] No Blacklist DNS List

On Fri, 18 Apr 2008, Ian Eiloart wrote:

| I hope you mean that if the reverse DNS entry for the sending IP address
| ends in wellsfargo.com then you'll whitelist the address.

Yep - I'm pretty sure this is what Marc P means. Need to check both:

- The rDNS entry for the sending IP matches *.wellsfargo.com

- The forward DNS entry for the resulting hostname machines the sending IP.

The latter check is needed to prevent a spammer who operates their own rDNS
from spoofing the hostname. The two checks together are sometimes known
as "forward-confirmed rDNS" (FCrDNS). Exim does this as a matter of course.

BTW, wouldn't a "No Blacklist List" be more simply described as a "white list" ?