[exim] Rate limit Outgoing mail based on recipient domain

Hi,

What I am looking for is a way to rate limit outgoing emails on the basis of
the domain to which the email is going to.

For instance, let's say I want only 5 emails per minute to yahoo.com, and I
don't want gmail.com emails to be affected once yahoo has reached it's rate
limit. I however want to resume sending yahoo emails once the limit has
expired.

I do not the sender to influence this rate limit at all, only recipients.

I don't want to use extra software to do this, I want it to be a "pure" exim
solution.

Thank you