🚀 go-pugleaf

The :INCLUDE:  syntax is an obsolete syntax that may have been in
RFC733, but is not in RFC822.  It is still in use, however, by some of
the older mailers.  There is no standardized syntax for mailing lists.
On Multics we have a number of address types for which there is no
standard syntax, and we handle them by using a special syntax in the
local-part of addresses.  In particular, we use the syntax
          To: "{list PATHNAME}"@MYHOST.ARPA
 for mailing lists.  Since the string is quoted it is treated as an
ordinary local-part by properly functioning software on other hosts.
                                        barmar