On Tue, Apr 20, 2021 at 10:51:29AM -0700, Stephen Satchell wrote: > > # Bind submission to specific interfaces, like lo and/or LAN > > # (add other options to taste) > > #127.0.0.1:submission inet n - y - - smtpd > > # -o syslog_name=postfix/submission > > #10.1.1.32:submission inet n - y - - smtpd > > # -o syslog_name=postfix/submission > > This would make clear how to bind Postfix to specific interfaces.
This is rather clearly documented: http://www.postfix.org/master.5.html Service type Specify one of the following service types: inet The service listens on a TCP/IP socket and is accessible via the network. The service name is specified as host:port, denoting the host and port on which new connections should be accepted. The host part (and colon) may be omitted. Either host or port may be given in symbolic form (see hosts(5) or services(5)) or in numeric form (IP address or port number). Host information may be enclosed inside "[]"; this form is necessary only with IPv6 addresses. Examples: a service named 127.0.0.1:smtp or ::1:smtp receives mail via the loopback interface only; and a ser- vice named 10025 accepts connections on TCP port 10025 via all interfaces configured with the inet_interfaces parameter. Note: with Postfix version 2.2 and later specify "inet_interfaces = loopback-only" in main.cf, instead of hard-coding loopback IP address information in master.cf or in main.cf. -- Viktor.
