the tag is using CGI.server_name to extract whatever.com address and than it's using cfmail tag to send mail to whom ever you specify;
example:
<cfif isDefined("sendto"

>
<cfmail
To="#sendto#"
From="#from#"
Subject="#Name# recommends trucks4.com">
Message from #name#: #message#
This message was sent from your #name# who visited #tellafriend_URL#. Your email address will not be distributed or sold to a third party, nor used for any other solicitation.
</cfmail>
<script language="JavaScript1.2">
alert('Email Sent');
</script>
</cfif>
<form action="" method="post">
<TABLE>
<input type="hidden" name="tellafriend_URL" value="<CFOUTPUT>#CGI.server_name#</CFOUTPUT>">
<TR><TD colspan="2">Tell your friends about this website! Just fill in your email and name and your friend's
emails separated by commas.</TD></TR>
<TR><TD>Your Email</TD><TD><INPUT TYPE="text" name="from"></TD></TR>
<TR><TD>Your Name</TD><TD><INPUT TYPE="text" name="name"></TD></TR>
<TR><TD>Friends Emails</TD><TD><INPUT TYPE="text" name="sendto"></TD></TR>
<TR><TD>Your personal message</TD><TD><INPUT TYPE="text" name="message"></TD></TR>
<TR><TD> </TD><TD><INPUT TYPE="submit" value="Send"></TD></TR>
</TABLE>
</form> Sylvano
dsylvano@hotmail.com
"every and each day when I learn something new is a small victory..."