/GATEWAY=option=host

    Optional. Default: None.

    An alternate route through which SMTP sends mail if delivery
    fails.

    o  [NO]ALTERNATE=host

       -  Alternate host or domain to which delivery is attempted.

       -  Used by ZONE, if a zone is defined, as the last chance for
          delivery (see the /ZONE qualifier).

       -  NOALTERNATE deletes an existing alternate destination.

    o  [NO]GENERAL_PURPOSE=host

       -  Gateway to handle non-SMTP mail, for example, UUCP
          addresses.

       -  NOGENERAL_PURPOSE deletes the specified destination for
          protocols other than SMTP.