You need to use a placeholder. In that, choose to "reaplace with html code" and put in some form code, like this:

Code:
<form action="signup.php" method="post">
<table summary="signup form">
<tr><td>Your Name:</td><td><input type="text" name="name" size="50" /></td></tr>
<tr><td>Your Email address:</td><td><input type="text" name="email" size="50" /></td></tr>
<tr><td>Who do you want to Contact?</td>

<td>
<select name="mydropdown">
<option value="wilma@company.com">Wilma Flintstone</option>
<option value="barney@company.com">Barney Rubble</option>
<option value="fred@company.com">Fred Flintstone</option>
</select>
</td>

<tr>
<td></td>
<td>
<input type="submit" value="Sign Up">
</td>
</tr>
</table>
</form>
Then, you would have a php file called signup.php (the ACTION of the form) which would then grab the POST variables and use the mail functions to fill the appropriate values as needed. There are a lot of freely available php scripts to handle this part.

Does that help?