George Ficzeri:
> Hello.
>
> I hope these aren't silly questions: How does Postfix (2.9.6) determine
> whether the local mail system is backup or primary MX when
> permit_mx_backup is specified in main.cf? Is it just MX record
> priorities in DNS?
By default it will act as primary or backup MX server, but you can
require that primary MX hosts must be in specific local or remote
networks with the permit_mx_backup_networks feature.
Wietse
> http://www.postfix.org/postconf.5.html#permit_mx_backup
> * 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.
>
> Does this mean a MX record pointing to a mail host w/ permit_mx_backup
> all that's needed to relay to it?
>
