Benny Pedersen:
> D'Arcy Cain skrev den 2020-11-23 15:18:
>
> > :0 Wh: msgid.lock
> > | formail -D 65536 $HOME/.msgid.cache
> >
> > In other words, the message ID "" was considered a duplicate after the
> > first one.
>
> if you use postfix there would be uniq msgid always, eq postfix ensures
> there is always fqdn in msgid aswell, many mua's does not ensure the
> fqdn part
Postfix 2.6 and later don't add a Message-ID header, unless the
message comes from a "local" source. That header is a combination
of a time stamp and the Postfix $myhostname value, so it is unique
as long as both values are unique.
Wietse