backward compatibility in mail errors postfix

hi I see this is my mail errors

Oct 26 00:48:06 cloud2 postfix[1940]: Postfix is running with backwards-compatible default settings
Oct 26 00:48:06 cloud2 postfix[1940]: See Postfix Backwards-Compatibility Safety Net for details
Oct 26 00:48:06 cloud2 postfix[1940]: To disable backwards compatibility use “postconf compatibility_level=2” and “postfix reload”
Oct 26 00:48:06 cloud2 postfix/postfix-script[1946]: stopping the Postfix mail system
Oct 26 00:48:06 cloud2 postfix/master[1337]: terminating on signal 15
Oct 26 00:48:06 cloud2 postfix[1956]: Postfix is running with backwards-compatible default settings
Oct 26 00:48:06 cloud2 postfix[1956]: See Postfix Backwards-Compatibility Safety Net for details
Oct 26 00:48:06 cloud2 postfix[1956]: To disable backwards compatibility use “postconf compatibility_level=2” and “postfix reload”
Oct 26 00:48:06 cloud2 postfix/postfix-script[2020]: starting the Postfix mail system
Oct 26 00:48:06 cloud2 postfix/master[2022]: daemon started – version 3.4.7, configuration /etc/postfix
Oct 26 00:48:06 cloud2 dovecot: master: Warning: Killed with signal 15 (by pid=2026 uid=0 code=kill)
Oct 26 00:48:08 cloud2 dovecot: master: Dovecot v2.3.8 (9df20d2db) starting up for imap, pop3 (core dumps disabled)

Is there a way when users install cyberpanel they wont encounter this so @usmannasir can fix during install of cyberpanel so the files are already setup correctly instead of getting the errors?
or do they have to read below and edit the files mentioned to get rid of the errors

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

as people may have customizations I’m not sure that upgrades can be safely done on this unless a standardized and safe upgrade method for the config is setup, but I do agree having the newer style defaults for Dovecot 2.3 would be nice.

The warnings are not a huge deal and it should not affect functionality.

If you want to try a newer Dovecot 2.3 style config and haven’t set up any email accounts yet or don’t mind removing them and setting them up again afterwards you can try using the below one which should use all the new formatting and auto create via auto vs the autocreate and other deprecated stuff

This one is also setup for sieve and spam to default into Junk mailbox for all accounts that part can be removed if not using it

Guide:
backup configs:
cp /etc/dovecot/dovecot.conf /etc/dovecot/dovecot.conf-bak
cp /etc/postfix/master.cf /etc/postfix/master.cf-bak
cp /etc/postfix/main.cf /etc/postfix/main.cf-bak

Please NOTE:
TO reverse these modifications the below commands can be used.
cp /etc/dovecot/dovecot.conf-bak /etc/dovecot/dovecot.conf
cp /etc/postfix/master.cf-bak /etc/postfix/master.cf
cp /etc/postfix/main.cf-bak /etc/postfix/main.cf
service dovecot restart && service postfix restart;
service dovecot status && service postfix status;

Install the required packages:

Ubuntu
apt-get install -y dovecot-managesieved dovecot-sieve net-tools pflogsumm

Centos
yum install nano net-tools dovecot-pigeonhole postfix-perl-scripts -y

mkdir -p /etc/dovecot/sieve/global
touch /var/log/{dovecot-lda-errors.log,dovecot-lda.log}
touch /var/log/{dovecot-sieve-errors.log,dovecot-sieve.log}
touch /var/log/{dovecot-lmtp-errors.log,dovecot-lmtp.log}
touch /etc/dovecot/sieve/default.sieve
chown vmail: -R /etc/dovecot/sieve
chown vmail:mail /var/log/dovecot-*

chown -R vmail:vmail /home/vmail
chmod 755 /home/vmail
find /home/vmail -type d -exec chmod 0755 {} \;
find /home/vmail -type f -exec chmod 0640 {} \;
chown vmail: -R /etc/dovecot/sieve
chown vmail:mail /var/log/dovecot-*

Setup Default sieve filter to put into spam.
nano /etc/dovecot/sieve/default.sieve
require “fileinto”;
if header :contains “X-Spam-Flag” “YES” {
fileinto “INBOX.Junk”;
}

Run this to compile the rules.
sievec /etc/dovecot/sieve/default.sieve

Empty the current dovecot config

/etc/dovecot/dovecot.conf

copy in the new base one via nano.
nano /etc/dovecot/dovecot.conf

dovecot.conf

Replace the lines in this with your hostname and domain postmaster email
hostname = server.example.com
postmaster_address = postmaster@example.com

Restart and check services are up and then test.
service dovecot restart && service postfix restart && service spamassassin restart;
service dovecot status && service postfix status && service spamassassin status;

Start tailing logs:
tail -f /var/log/{maillog,mail.log,mail.err,syslog}

Sent your test Junk email with the below in the body of the email:
XJSC4JDBQADN1.NSBN32IDNENGTUBE-STANDARD-ANTI-UBE-TEST-EMAILC.34X