qmgr warning: connect to transport private/retry

[Dan33l]

I am currently using module camptocamp/postfix, 1.8.0.

I have in logs of postfix the message : postfix/qmgr[2679]: warning: connect to transport private/retry: Connection refused

By running a command suggested by Wietse Venema (i used postfix upgrade-configuration), this added two lines in /etc/postfix/master.cf:

retry     unix  -       -       n       -       -       error
proxywrite unix -       -       n       -       1       proxymap

After some days with these settings added, i am not getting the warning message anymore .

I am currently using Ubuntu 16.04. And i don't know how to test this.

So, how do you prefer to proceed ?