error code 5xx with action as 421.

Hello everyone!

Do we have some 5xx error code, which drop connection immediately as it fo
421?

From docs:
"Use "421" reply codes for botnet-related RBLs or for selected non-RBL
restrictions. This causes Postfix 2.3 and later to disconnect immediately
without waiting for the remote SMTP client to send a QUIT command."

Thank you.

Alex.