Postfix help with "-o smtpd_client_restrictions=permit_sasl_authenticated,reject"

Hi - new to ISPConfig. I've recently successfully installed it, using this tutorial: layloyar.com/2019/04/how-to-deploy-ispconfig-3-on-ubuntu-19-04.html. I am in the process of learning it now.

However one thing I noticed in Postfix, was that this line wasn't available for uncommenting:
# -o smtpd_client_restrictions=permit_sasl_authenticated,reject

As things seem to be working so far, its not urgent, but I figure once I fully test the mail system this will probably cause errors. Can someone explain what this line is used for? Should I copy this into /etc/postfix/master.cf manually, or do I have to install install something first?

For clarification, this is on Ubuntu 19.04, on a VPS. Let me know if further details are needed. Thank you in advance for help.

 

http://www.postfix.org/SMTPD_ACCESS_README.html

"-o" sets an option
"smtpd_client_restrictions" sets the restrictions on which clients are allowed to connect (following, from left to right)
"permit_sasl_authenticated" (allows clients, which have authenticated via sasl)
"reject" rejects all others

The configuration in the tutorial you linked looks strange. Use one of the official tutorials, if you do not know what you are doing.

First three services in master.cf should look something like this:

Code:

smtp       inet  n       -       y       -       -       smtpd
submission inet  n       -       y       -       -       smtpd
    -o syslog_name=postfix/submission
    -o smtpd_tls_security_level=encrypt
    -o smtpd_sasl_auth_enable=yes
    -o smtpd_client_restrictions=permit_sasl_authenticated,reject
smtps      inet  n       -       y       -       -       smtpd
    -o syslog_name=postfix/smtps
    -o smtpd_tls_wrappermode=yes
    -o smtpd_sasl_auth_enable=yes
    -o smtpd_client_restrictions=permit_sasl_authenticated,reject

Note that in your tutorial, the smtps and submission daemons are commented out.

 

thank you!