One of our users received this notification from exchange (2007):
From: MAILER-DAEMON [mailto:postmaster@[
DOMAIN.COM]]
Sent: Monday, July 21, 2008 9:52 PM
To: [USER@
DOMAIN.COM]
Subject: Returned mail: Data format error
Dear user of [
DOMAIN.COM],
Your email account was used to send a huge amount of junk email during the
last week. We suspect that your computer had been infected and now contains
a hidden proxy server. We recommend you to follow our instructions in order
to keep your computer safe.
Have a nice day,
The [
DOMAIN.COM] support team.
(User name and domain info modded for anonymity)
This looks like some kind of message "send quota" has been overstepped, but
I haven't any idea where to go to change its properties.
The end user indicated that they had indeed been very active on serveral DLs
recently. The user's machine is not hosting any hidden proxies.
Header info confirms send origin as being our Exchange server.