Comment 6 for bug 1643249

After upgrading that server to Ubuntu 18.04, I still get the same error trying to start amavis (amavisd-new 1:2.11.0-1ubuntu1).

However, at the Redhat bug tracker, there is a similar issue reported and the suggested fix there also works for me:
In /etc/amavis/conf.d/50-user simply add
    $inet_socket_bind = '127.0.0.1';

After that, amavis is able to properly bind to ports 10024 and 10026 and start up without issue.