No, it isn't. The subject line of the email was

"Your e-mail to IBObjects@yahoogroups.com is being challenged"

and ibobjects is a mailing list that I've been a member of for the last
five years and I've seen the message resulting in that challenge reach the
list. The sender of the challenge has to be one of the 1500 subscribers
ibobjects@yahoogroups.com, and everyone who sends a message to
ibobjects@yahoogroups.com will be challenged because of this one
subscriber. If a person actively chooses to be part of a mailing list, he
cannot demand that everyone sending to this list should take a challenge
from him.

Svein Erling Tysvær
-copy sent to ibobjects@yahoogroups.com

At 14:59 18.02.2005, you wrote:

>The recipient of the e-mail and as such the sender of the challenge is
>indicated in the subject line of the e-mail. Mail challenge is activated by
>choice of the subscriber.
>
>
>--
> Mark Hennessy
> Cloud 9 Internet
> +1 914 696-4000
> http://www.cloud9.net
>-----Original Message-----
>From: Svein Erling Tysvær [mailto:svein.erling.tysvaer@...]
>Sent: Friday, February 18, 2005 5:34 AM
>To: webmaster@...
>Cc: ibobjects@yahoogroups.com
>Subject: Abuse of opt-in
>
>I just received an email with a challenge:
>
>https://customercare.cloud9.net/mailchallenge.cgi?challenge-id=1a5c5c49cc7681
>46756106f3573a36c3
>
>Challenging would have been fair if I tried to send an email to the person
>in question (whomever it might be). However, I answered a question at the
>mailing list IBObjects@yahoogroups.com, a mailing list that has over 1500
>subscribers. It would be ridiculous if every member posting to this list
>had to answer a challenge for every member that used cloud9 (luckily, I
>think it is just one person who recently subscribed). I don't know whether
>it is you or your clients fault (I suspect the latter), but please take
>appropriate action anyway (that action being either making sure that mails
>to ibobjects@yahoogroups.com gets through, or telling us whom (email
>address) makes the challenge so that we can ban him/her from our list.
>
>Yours faithfully,
>Svein Erling Tysvær