Is there a way to block a local/unix user (or a list of local users) from sending mails via
As suggested by @Gilles, I'm leaving here what I did so others can benefit from it.
My machine's host is
abcxyz.ovh.net and the user I was trying to block was
I ended up creating
/etc/postfix/sender_access with the following content:
Then I compiled it with
Finally, I added this to my Postfix configuration:
smtpd_recipient_restrictions = check_sender_access hash:/etc/postfix/sender_access, ..., ..., ..., ...