Stop emails tagged as coming through to RT

Hi, we get tickets with [SPAM] in the subject field come through to RT, in
the procmail config, the following is set to stop this

Filter out Potential spam marked up by the Spamchecker.

:0w:
*^X-org-Spamcheck
/var/rt/emails-marked-spam

This will check the email headers for X-org-Spamcheck

Our spam checker tags spam emails with a subject tag [SPAM] and a header
flag “X-org-Spamcheck: Spam”

The spelling of “X-org-Spamcheck” was incorrect and have rectified it, is
this the correct way to filter out SPAM from the RT even if it gets past
the MTA?

Thanks