Whilst I hate all things criminal, I do have a certain respect for the social engineering that goes into much of it. Spam is no exception, but the vast majority of it is low-quality 'scattergun' selling. Every once in a while though, you get a good 'phish'; I've just received this one:
From: Mail Delivery Subsystem [noreply@[domain name]]
Subject: Returned mail: see transcript for details
Dear user of [domain name],
We have detected that your e-mail account has been used to send a large amount of unsolicited commercial email during this week. Probably, your computer had been compromised and now contains a hidden proxy server.
Please follow instructions in order to keep your computer safe.
Best wishes,
[domain name] support team.
(attachment: message.scr)
See! Clever stuff. For once it's a well written, credible email. However they chose to send it to the administrator of the domain, so of course I knew it was fake. We all know that the message.scr attachment is going to quietly install the proxy server, and is then going to send oodles of mail (although unlikely it'll appear to be from my account).