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 >> >> Which of those restrictions do I specify, and where, and why aren't they set >> by default? >
(I missed the original mail, so I'm replying here.) 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.
