On Monday, 20 July 2020 18:25:28 BST Michael Orlitzky wrote: > On 2020-07-20 12:39, antlists wrote: > > On 20/07/2020 15:55, Peter Humphrey wrote: > >> fatal: in parameter smtpd_relay_restrictions or > >> smtpd_recipient_restrictions, specify at least one working instance of: > >> reject_unauth_destination, defer_unauth_destination, reject, defer, > >> defer_if_permit or check_relay_domains --->8 > If you don't specify one of those restrictions in one of those places, > your mail server is an open relay. Postfix doesn't let you do that. > > One of them is set by default; smtpd_relay_restrictions end with > defer_unauth_destination on new installs.
That command doesn't appear in my main.cf. I ended up adding the following to main.cf: ------- # Allow connections from trusted networks only. smtpd_client_restrictions = permit_mynetworks, reject # Don't talk to mail systems that don't know their own hostname. smtpd_helo_restrictions = reject_unknown_helo_hostname # Don't accept mail from domains that don't exist. smtpd_sender_restrictions = reject_unknown_sender_domain smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination # Block clients that speak too early. smtpd_data_restrictions = reject_unauth_pipelining ------- Those came from http://www.postfix.org/SMTPD_ACCESS_README.html. I don't know what use the page https://wiki.gentoo.org/wiki/Postfix is: it hasn't helped me at all. As usual, though, the kind people on this list certainly have! Thank you all. -- Regards, Peter.