[exim] Recipient Ratelimit

I am attempting to setup ratelimit based on recipient. I am unable to
limit the number of emails sent to a specific recipient. This is the
configuration I am using
(/etc/exim4/conf.d/acl/10_exim4-config_smtp_rcpt):

acl_smtp_rcpt:

defer
ratelimit = 2 / 1h / $recipients
message = Rate limit exceeded for $recipients $sender_rate/$sender_rate_period
recipients =mytest@???
log_message = Ratelimit: $recipients rate limit / $sender_rate_period DEFFERED

This is the email command I am using on the localhost of the exim server:
mailx -S smtp=172.18.1.35 -r dev@??? -s Test -v
mytest@??? < body.txt

Let me know if you have any thoughts or suggestions.

Rich