When I theorized,
| > It is possible that the perpetrator deliberately loaded its to quota
| > so that
| > any incoming mail would be bounced for going over quota; Chuq didn't
| > say what
| > reason the bounces gave.
| it was mailbox unavailable, not mailbox full.
In a fantasy world, that could mean that Hotmail had shut it off for spamming.
Seriously, Hotmail might just coincidentally have been having problems. AFAIK
there is no way for a user to cancel a Hotmail account except by several
months of disuse.
We can rule out forged From: lines pointing to a Hotmail address that never
existed, because that address had received the confirmation request and
perhaps some posts or digests.