Wietse Venema:
> > * permit_mx_backup
> > Permit the request when the local mail system is backup MX for the RCPT
> > TO domain, ...
> > <snip>
> > *Safety: as of Postfix version 2.3, permit_mx_backup no longer accepts
> > the address when the local mail system is primary MX for the recipient
> > domain.
I suppose that is still in effect (my previous reply is based on
the older implementation). You can specify with permit_mx_backup_networks
where the primaries must be located.
> > Does this mean a MX record pointing to a mail host w/ permit_mx_backup
> > all that's needed to relay to it?
You also need relay_recipient_maps or reject_unverified_recipient,
otherwise your server will accept non-existent email addresses and
will send massive numbers of bounces to innocent people.
Wietse
