[Mimedefang] Large image-only spam

[Mike Grau]

Hello.

Could I get some input on how folks deal with image-only
spam. I'm running Sendmail->Mimedefang-2.39->SpamAssassin-2.63.
The problem is that I'm getting image-only spams that are well
over the threshold message size we've set for scanning messages
with spamassassin. My machine has rather limited resources.
Is there a good cheap method within Mimedefang to deal with this
or would it be cheaper to raise the threshold for running messages
though SA? Perhaps set the size of the message for handing to SA 
conditionally dependent upon the recipient or X-Mailer header?

See sample below relayed through mas-b3f6.adsl.wanadoo.nl

Some headers:

   X-Mailer: The Bat! (v1.52f) Business
   MIME-Version: 1.0
   Content-Type: multipart/related;
           type="multipart/alternative";
           boundary="8E4E1D38DB4.3F.5CF."


And the message body:

--8E4E1D38DB4.3F.5CF.
Content-Type: multipart/alternative;
         boundary="8E4E1D38DCC.3F.5CF."


--8E4E1D38DCC.3F.5CF.
Content-Type: text/html;
Content-Transfer-Encoding: quoted-printable

<center>
<a href=3D"http://www.yesit.3322.xxx/17/index3.php">
<IMG SRC=3D"cid:3.gif" ALT=3D"" border=3D"0"></a>
</center>

--8E4E1D38DCC.3F.5CF.--

--8E4E1D38DB4.3F.5CF.
Content-Type: image/jpeg;
         name="3.gif"
Content-Transfer-Encoding: base64
Content-ID: <3.gif>

R0lGODlh4AGQAfcAAAAAAP///9gcIO5XWatFRtQ2PTswMS8NEsJdbkolM9yWtKgIWPjY6Kw4^M
dZslZcoIeIoIU+stmOtVq/YIlPiAx/jI5efY4b0kg9I1lfhow6tzlu+v1ufI3KsIdZgIaHAJ^M

etc., etc.

--8E4E1D38DB4.3F.5CF.--