That's what we call the petsupermaket spammer. It seems to be replying to most people who post on debian-devel, debian-user and sometimes some of our other lists. We haven't been able to match a subscriber to this, and it's not happening all the time. If anyone can find something that makes is consistently go off, please let us at listmaster@lists.debian.org, it'd be quite helpful, as we haven't figured it out yet. It went away for a while two months ago or so and recently came back. We have been trying to reach someone at the ISP, but it doesn't appear we've had much luck so far. We're trying to avoid having to take some more drastic measures.
Would it be too drastic to kindly ask petsupermarket@uol.com.br to either nag his/her provider to stop these e-mails or alternatively subscribe via another e-mail account or view the mails on one of the web servers?
In my humble opinion the thousands of petsupermarket e-mails delivered to ordinary posters justify such an action. If this spamming should happen to continue, listmasters should probably unsubscribe petsupermarket. After all, noone knows, if petsupermarket actually reads his/her e-mails from d-u.
Speaking for myself, I would not want to have such a flood of spam sent out to thousands -- just because I happen to be subscribed to a mailing list...
Johannes