Undelivered message for bad_extensions files

I added zip and rar extensions to data/conf/rspamd/local.d/mime_types.conf to have messages containing these type of messages treated as spam.

This way I’m getting these messages bounced as soft spam.

The sender receives an Undelivered Mail message with this error:

554 5.7.1
    This message does not meet our delivery requirements (in reply to end of
    DATA command)

Is it possible to customise this message, only if the message is rejected due to bad_extensions attached files?

Thank you very much!

Bump.
I also want to have more descriptive rejection messages. What’s the best way to handle this. Or at least point me in the right direction.