code: public void setProxyport(double proxyport) throws ApplicationException {
  	try {
  	    smtp.getProxyData().setPort((int) proxyport);
  	}
  	catch (Exception e) {
  	    throw new ApplicationException("attribute [proxyport] of the tag [mail] is invalid", e.getMessage());
  	}
      }
docs: set the value proxyport The port number on the proxy server from which the object is requested.
  Default is 80. When used with resolveURL, the URLs of retrieved documents that specify a port
  number are automatically resolved to preserve links in the retrieved document.
  
  @param proxyport value to set
  @throws ApplicationException