POSTFIX - header checks not working as expected.

[dannyboy1121]

Hello - I'm trying to get Postfix to do what I've done previously with the old Pfsense Postfix setup (when that was supported) by using header checks to block traffic claiming to be from certain locations.

What I'm seeing is that the regex works but Postfix isn't supporting REJECT

e.g:

/^From:.*hotmail.com/ REJECT

Gives log entry -

warning: unsupported command in smtp_header_checks map: REJECT

Then the mail passes rather than gets blocked. Same for DISCARD.
Is that right? The OPNsense implementation doesn't support it? The alternative is to reject specific senders, but that only appears to work with full addresses, not partial as above.

Any help / ideas would be appreciated.