From: Patrick Fernie <patrick.fernie@...>
Date: 2005-09-24T05:25:59+09:00
Subject: Re: On accidental unsubscribe messages

Wow, talk about being dense (me, not you). A simple spoofed email
worked perfectly. Thanks!

On 9/23/05, Jacob Fugal <lukfugl@gmail.com> wrote:
> As long as you have access to something the likes of sendmail (plenty of
> perl modules I know of and probably some ruby ones I don't know of) you cand
> send a mail with any address you want. I get spam that claims to be from my
> brother's email address (despite the first line being "Hi, my name is
> LaFonda!") all the time.
>
> HOWEVER, some (unfortunately not as many as there should be) servers will
> perform a reverse DNS lookup on the domain you *claim* to be sending from,
> and reject the email if it doesn't match the actual senders IP.
>
> So... the questions are:
>
> 1) Does ruby-lang.org <http://ruby-lang.org> (or any intermediate SMTP
> relay) perform RDNS checking?
> 2) Do you have access to some sendmail-ish program/library?
>
> If the answers are No and Yes, respectively, than you can spoof the old
> address and unsubscribe yourself. Otherwise... good luck getting a hold of
> the human admin (or hacking into the old address' server).
>
> Jacob Fugal
>
>