[Users] How to hide sender IP address and host name?

[Paul]

On Fri, 16 Feb 2018 16:38:04 +0200
Removed GDPR <removed-gdpr at example.com> wrote: 

> Is there any requirement (e.g. by some technological standard) that
> the original sender's IP address must be in the headers or that is
> simply a configuration up to the sysadmin who does configures the
> SMTP server?

postfix can be configured to anonymise them, for example.

with regards

Paul