How is this possible?

[soccerdude]

Hi I was at my uncle's house a couple of days ago and I was on his computer. I went to the site https://www.grc.com/x/ne.dll?bh0bkyd2 . I wanted to do those security scans and as I scrolled down the page and was about to click proceed when I noticed he doesn't have a"reverse DNS". How is this possible? And if it adds more security how do you do it? Oh and what does "reverse DNS" do?

 

[PC eye]

That is the lack of a spam filter. The ISP compares sender name to valid IP addresses through a data base. If the spammer uses a bogus name which doesn't match up with the IP address the email is blocked. Too high a setting on filters can also block email with valid signatures.

 

[SirKenin]

Reverse DNS simply turns an IP into a hostname. For example, it will change 64.233.167.99 into www.google.com.

That's all.

 

[PC eye]

A full description can be found at http://en.wikipedia.org/wiki/Reverse_DNS_lookup There is also a few external links for additional information.

 

[soccerdude]

Thanks

 

[PC eye]

You're Welcome! Setting "rules" with the ISP or Outllook can be a nuisance since you don't know if you will unintentionally block any good mail coming in. But without good filtering you get nothing but ssssssspamationnnn at times. At least IE 7 will allow blocking entire domains. If something comes in from AOL or Earthlink for example you can block "everything" being sent from a spammer's domain.