How would you write a rule to do a DNS lookup, not of the IP address but
of the host name? I can do this in Exim but looking to do the same thing
using SA.
I have created a name based DNS list instead of just IP based. The
request as follows:
<hostname>.hostkarma.junkemailfilter.com
A return of 127.0.0.1 = whitelisted
A return of 127.0.0.2 = blacklisted
A return of 127.0.0.3 = yellowlisted
Example - run this:
dig hermes.apache.org.hostkarma.junkemailfilter.com
Now - here's the trick. In order to do this right you can't just use the
host name unless you verify it. The RDNS has to be checked to verify
that the host name resolves back to the original IP address. But once
you do that this lookup would be very useful.
So - how do you write a rule/plugin to use this?
