Eric Cunningham:
> > transport_maps simply routes accepted messages by overriding DNS.
>
> That's what I want to continue to do, as had occurred happily before the
> postfix upgrade.
>
> > To accept mail, the envelope recipient *must* be in mydestination,
> > relay_domains, virtual_alias_domains or virtual_mailbox_domains.
> > All may be a type:table input for lookups.
> >
> > You should have *one* domain in *one* address class.
> >
> > See http://www.postfix.org/ADDRESS_CLASS_README.html for details
>
> That's all well and good, but I shouldn't need to list all the MX'ed
> machines in any of those.
Yes, you do. If you don't list a domain in some class, then Postfix
will reject its mail with Relay access denied.
Wietse