I just re-enabled SpamAssassin on my server after a couple issues required turning it off for about a day, and it immediately flagged its very own ‘now enabled’ email notification as spam:

Received: from localhost by box584.bluehost.com
 with SpamAssassin (version 3.3.0);
 Thu, 24 Mar 2011 09:28:54 -0600
From: "Spam Assassin" <spamassassin@localhost>
Subject: ***SPAM*** 
X-Spam-Checker-Version: SpamAssassin 3.3.0 (2010-01-18) on box584.bluehost.com
X-Spam-Flag: YES
X-Spam-Level: *****
X-Spam-Status: Yes, score=5.5 required=2.0 tests=AWL,BAYES_40,FH_FROMEML_NOTLD,
 MISSING_DATE,MISSING_HEADERS,MISSING_MID,MISSING_SUBJECT,NO_HEADERS_MESSAGE,
 NO_RECEIVED,NO_RELAYS shortcircuit=no autolearn=no version=3.3.0
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="----------=_4D8B6336.C4060404"

This is a multi-part message in MIME format.

------------=_4D8B6336.C4060404
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit

Spam detection software, running on the system "box584.bluehost.com", has
identified this incoming email as possible spam.  The original message
has been attached to this so you can view it (if it isn't spam) or label
similar future email.  If you have any questions, see
the administrator of that system for details.

Content preview:  Spam Assassin has been enabled on this account [...] 

Content analysis details:   (5.5 points, 2.0 required)

pts rule name              description
---- ---------------------- --------------------------------------------------
1.1 FH_FROMEML_NOTLD       E-mail address doesn't have TLD (.com, etc.)
-0.0 NO_RELAYS              Informational: message was not relayed via SMTP
1.0 MISSING_HEADERS        Missing To: header
-0.0 BAYES_40               BODY: Bayes spam probability is 20 to 40%
 [score: 0.3736]
0.5 MISSING_MID            Missing Message-Id: header
1.8 MISSING_SUBJECT        Missing Subject: header
-0.0 NO_RECEIVED            Informational: message has no Received headers
1.4 MISSING_DATE           Missing Date: header
0.0 NO_HEADERS_MESSAGE     Message appears to be missing most RFC-822 headers
-0.2 AWL                    AWL: From: address is in the auto white-list

------------=_4D8B6336.C4060404
Content-Type: message/rfc822; x-spam-type=original
Content-Description: original message before SpamAssassin
Content-Disposition: inline
Content-Transfer-Encoding: 8bit

From: "Spam Assassin" <spamassassin@localhost>

Spam Assassin has been enabled on this account

------------=_4D8B6336.C4060404--

The irony.  It burns.