Linux : inet_protocols: IPv6 support is disabled: Address family not supported by protocol

By | October 18, 2014

Getting theses output warning on the console when starting or restarting the Postfix daemon?

postqueue: warning: inet_protocols: IPv6 support is disabled: Address family not supported by protocol
postqueue: warning: inet_protocols: configuring for IPv4 support only

This mean that Postfix is actually configured to listen on both IPv4 and IPv6 protocols but you do not have any IPv6 address configured on that server.

To resolve this issue, you just have to tell Postfix to strictly use IPv4.

1. Edit the main Postfix configuration :

2. Locate the “inet_protocols” statement :

3. Change “all” to “ipv4” as followed :

4. Restart Postfix :