Author: Marc Perkel Date: To: Eli CC: exim users Subject: Re: [exim] Automatic Whitelist Generation - Why wouldn't this work?
Eli wrote: >> Maybe I'm missing something. Can I take one of my IP addresses and make
>> the RDNS appear to be from xxx.amd.com and make a lookup on xxx.amd.com
>> agree?
>>
>
> Yes you can. That's why reverse DNS information is pretty much completely
> useless when doing any type of tracing. I suggest you read up on DNS
> servers and how zonefiles work et al before going too far on speculations
> regarding DNS, especially if you're using the results to filter stuff (email
> in this case).
>
> Eli.
>
>
> If you do a reverse lookup and then check to see if the name resolves to
the IP that you looked up you can tell it's fake.
