[vs] DNS Wasserturm

                                                                                               monster  varphi  teal
                                                                                                   \      |      /
                                                                                                    \     |     /
                                                                                                        [IPv6]
                                                                                                      SMARTHOST
                                                                                                          |
                                                                                                          v   
    foo@theater.foldr.org ---------------------> sendmail@lambda.foldr.org -----------------> sendmail@theater.foldr.org
    bar@stargate.theater.foldr.org                  MX lambda.foldr.org         STARTTLS              RELAY/STARTTLS
                                                            ^                    +VERIFY       
                                                            |                                            |
                                                            |                                            |
                                                            |                                            v
                                                     RELAY: .foldr.org                        stargate.theater.foldr.org
                                                            SMTP-AUTH
	

See also:

<%method kata>.