[exim] Deny when from and to are the same

I have two rules set up in acl_smtp_rcpt:

  deny
    hosts = ! +relay_from_hosts
    condition = ${if eqi{$sender_address}{$local_part@$domain}}
    log_message = Same sender and recipient address

  deny
    hosts = ! +relay_from_hosts
    condition = ${if eqi{$reply_address}{$local_part@$domain}}
    log_message = Same sender and reply address

I'm trying to check when the From: address is the same as the To:
address and the mail is coming from a host outside my accepted network.

I just received a message where the addresses in From and To were the
same but neither of these rules captured it.

What am I missing to perform this check and deny spam messages like this?