You will have to expand on:
"$message = the checkboxes"
You are on the right track when you say you will need to use an array for checkboxes. If you want multiple values returned to your script, you will need to name the checkboxes like so:
<b>
<INPUT TYPE="checkbox" NAME="myCheckboxes[]" VALUE="item001">Our Great Product!
<INPUT TYPE="checkbox" NAME="myCheckboxes[]" VALUE="item002">Another Great Product!
<INPUT TYPE="checkbox" NAME="myCheckboxes[]" VALUE="item025">Yet Another Great Product!
</b>
Not that all the form's checkboxes have the same name with "[]s" at the end. This will cause all of the checked values to be returned to your script in an array with the name "$myCheckboxes".
You then need to access those values through a loop:
<b>
$valueArray = $HTTP_POST_VARS[$myCheckboxes];
$loopCount = sizeof($valueArray);
$idx = 0;
while ($idx < $loopCount):
// do something with $valueArray[$idx]
$idx++;
endwhile;
</b>
HTH
-- Rich Rijnders
-- Irvine, CA US