Just wrap the whole thing in the <p>.

I don't know why we needed that subbox anyway.

Previous commit definitely did not work.

www/conservancy/templates/frontpage.html

@@ -49,12 +49,13 @@
       and other social networks, too.  Look
       for us everywhere and follow/like us!</p>
 
-        <form id="subbox" method="post" action="https://lists.sfconservancy.org/mailman/subscribe/announce">
+<p>
+        <form  method="post" action="https://lists.sfconservancy.org/mailman/subscribe/announce">
           You can also subscribe to Conservancy's low-traffic email announce
           list
           (and <a href="http://lists.sfconservancy.org/pipermail/announce/">read
           its archives</a>): <br/><input name="email" placeholder="person@example.org"/><input type="submit" name="email-button" value="Subscribe"/>
-        </form>
+        </form></p>
 </div>
 
 <div class="column column-large">