Postfix - Address Family Not Supported

Basically, postfix was configured with ipv6 support when the OS does not provide it

Starting Postfix Mail Transport Agent: postfixpostmulti: warning:
inet_protocols: disabling IPv6 name/address support: Address family not supported by protocol
postmulti: warning: inet_protocols: disabling IPv6 name/address support: Address family not supported by protocol
postfix: warning: inet_protocols: disabling IPv6 name/address support: Address family not supported by protocol

Solution:

sudo postconf -e 'inet_protocols = ipv4'
sudo /etc/init.d/postfix restart