IP ---> e-mail

elliot smith (smithe@minot.com)
Mon, 3 Jun 1996 21:15:46 -0500

some people have showed interest on how to put an e-mail address to
an IP so here is a more detailed explanation.

Let's say you see my IP on cu-see-me. right now it's
(Every time I connect to my ISP I get a different IP)

Some ISPs do not run finger. I think ISPs should be required to run
finger because we don't need people messing up the 'net anonymously.
But finger is a security risk because it gives out information. The
more information a hacker has, the easier it is for them to hack into
a system. But Unix is so chock full of security holes I do not think
that running finger is going to make things any worse. But anyway...

Reverse-dns, finger, and whois information needs to be obtained with
a client. You can get a client for your PC for each of these.
reverse dns For Macintosh:

finger and whois is likely to be installed on your unix account.
I think that you can telnet to internic.net to do whois queries.
There are also gateways to such programs on the web
Finger gateway: http://www.brandonu.ca/~ennsnr/Resources/Roadmap/map25.html
reverse dns gateway:

So run my IP,, through the rdns gateway and you get

Obviously, my ISP is minot.com. You can complain to
postmaster@minot.com about me, telling exactly when I was on and what
I did, and the administrators of the system can check their logs to
see if I was on at that time and maybe even see if I did access that
system/send a large e-mail(s), or whatever else.

If you don't get results from minot.com, you can complain to their
ISP. You find this info doing a whois minot.com. whois
ppp24.minot.com will likely get you nowhere. To find minot.com's
ISP, do a whois on their nameserver, which will be given to you in
the whois results.

If you finger minot.com (you may have to finger ""@minot.com) you
will get a list of all users currently connected. If I were to log
out fast enough, I would not show up in the finger results. The
particular finger program minot.com is running does not give the IP
of each person, so you would have to finger each individual user to
see their IP. Actually, even then I can't seem to list IPs, so I
guess you can't get my e-mail address from my IP.

There is such a thing as an rdns lookup table for indivudal users
that some ftp sites use to verify your identity, but I'm not sure how


http://minot.com/~smithe/ http://admin.gat240.misu.nodak.edu/
PPP setup info. for Macintosh, PWebP -- a searchable web page index
PGP, Francais/English