Hello ! My server is debian 10, apache with ispconfig 3. I want to remove / disable postfix/smtpd because I have too many requests for this, maybe hachers... Because of that my CPU is overloading and I want to remove / disable this option for all of my websites. Can you help me to resolve this problem?
Should be Code: systemctl stop postfix; systemctl disable postfix and then disable any monitoring which might restart it (eg. under System > Service Config and anything you may have setup like monit).
How did you try it? What happened? Is postfix running? If you stopped postfix and it stays stopped, it should no longer make new log lines.
Perhaps you get new logs from local submissions, rather than from smtp? What does "systemctl status postfix" show?