There is a problem in the HTML. I saw in there where some of your properties for one of the td tags doesn't have a closing " and is therefore makeing a large chunk of the HTML as part of the property.
Because of the errors in the red parts of the HTML, its not rendering parts of the e-mail properly.
<HTML>
<BODY>
<table border=0 align=center width=100% cellspacing=0 cellpadding=0 bgcolor=#BFBFBF>
<tr>
<td>
<table border=0 width=100% cellspacing=1 cellpadding=4>
<TR>
<TD height=26 width=100% align=center bgcolor=white" background="bg5.gif>
<font face=Verdana, Arial, Helvetica size=2 color=black>
<b> NewsLetter - Test</b>
</font>
</td>
</tr>
<tr>
<td align=center bgcolor=white" background="bg5.gif>
<font face=Verdana, Arial, Helvetica size=2 color=black>
This is not SPAM, you requested to join the Newsletter list
</font>
</td>
</tr>
<tr>
<td bgcolor=#8c8c8c>
<font face=Verdana, Arial, Helvetica size=2 color=#e9e9e9>
Newsletter for 7/28/2005:
<br><br>
<img border=0 src="http://www.driftaustralia.com.au/Rd3_promo.jpg">
<br><br>
<font face=Verdana, Arial, Helvetica size=2 color=#e9e9e9>
You can use this area for a closing message, if not delete this before it is sent.
</font>
.
.
.
.
etc.
<