My suspicion is that your address is being placed into the "Bcc" portion of the originating spam source and the actual addressees are all there instead of in the "To" field......
That's a good thought, so I just tried it, and my e-mail got to me like so:
From: Artie (Edited) <(Edited)@verizon.net>
Date: May 29, 2011 7:59:05 PM EDT
To: Undisclosed recipients: ;
Received: from [192.168.1.46] ([unknown] [(Edited)]) by vms173001.mailsrvcs.net (Sun Java(tm) System Messaging Server 7u2-7.02 32bit (built Apr 16 2009)) with ESMTPA id <0LLZ005Y9EMH39D0@vms173001.mailsrvcs.net> for (Edited)@verizon.net; Sun, 29 May 2011 18:59:06 -0500 (CDT)
Mime-Version: 1.0 (Apple Message framework v1084)
X-Mailer: Apple Mail (2.1084)
Presumably, the "Undisclosed recipients" refers to the Bcc address, but the two red (Edited) addresses disclose it.
I guess each mail server handles such stuff differently?
But it could explain my spam. Hmmm... I'll have to pay closer attention next time.