public function deleteExternalAccount($mail)
{
$account[Horde_Kolab_Server_Object_Kolabpop3account::ATTRIBUTE_OWNERUID] = $this->getUid();
$account[Horde_Kolab_Server_Object_Kolabpop3account::ATTRIBUTE_MAIL] = $mail;
$object =& Horde_Kolab_Server_Object::factory('Horde_Kolab_Server_Object_Kolabpop3account', null, $this->server, $account);
$object->delete();
}