Authorized_submit_users with relay

iam trying to block certain authenticated user by email from sending via smtp via postfix.
ive configured this in my

authorized_submit_users = !/etc/postfix/nosend, static:all

and added both email and the virtual mapped user of the email to the nosend file and its not working

could it be because i have relay set to external smtp provider?

if yes, how do i solve this?
how do i block an email from sending email?

thank you :slight_smile:

OS type and version Ubuntu 20.04.5 LTS
Webmin version 2.001

is a user? maybe just someone

its just example
my real user is a user email of a virtual server in virtual min