On Tue, Nov 17, 2015 at 03:26:55PM +0000, Neil Smith wrote: > On Tuesday 17 Nov 2015 14:43:50 Viktor Dukhovni wrote: > > > > smtpd_recipient_restrictions = > > > permit_sasl_authenticated > > > permit_mynetworks > > > permit_mx_backup > > > check_recipient_access hash:/etc/postfix/recipient_checks > > > reject_unauth_destination > > > > Notice that cute little "permit_mx_backup" in the restriction > > list before "check_recipient_access"? :-) > > If you don't mind, could you please explain why that's a problem? The > recipient checks addresses aren't for any of the mxbackup domains. I don't > understand how allowing forwarding of mail for backup.com will mean the > acceptance of mail for example.com.
See: http://www.postfix.org/postconf.5.html#permit_mx_backup Read the description attentively. In general, permit_mx_backup is a bad idea, instead configure "relay_domains" explicitly and get rid of permit_mx_backup. Don't forget about "relay_recipient_maps". In any case your setting of http://www.postfix.org/postconf.5.html#permit_mx_backup_networks is also suboptimal, these really should be addresses, not hostnames. -- Viktor.