Postfix is a popular mail transfer agent (MTA) used for routing and delivering email messages between mail servers. By default, Postfix logs the client IP address and hostname in its mail logs, which can be useful for troubleshooting and analysis.
However, if you want to hide the client IP address or hostname from the mail logs, you can use the anonymize_sender configuration parameter in Postfix. When this parameter is set, Postfix will replace the client IP address or hostname with a fixed string in the mail logs.
To enable this feature, you can add the following line to your main.cf configuration file:
anonymize_sender = yes
After making this change, you will need to reload or restart Postfix for the configuration to take effect.
Note that hiding the client IP address or hostname in the mail logs may make it more difficult to diagnose issues related to specific clients or hosts. Therefore, this feature should be used with caution and only when necessary for privacy or security reasons.