[exim] Rate-limit queue-processing per domain

Hi!

I've tried to find information on how to rate-limit the messages that are
_already_ placed in the queue, but with no luck.

All rate-limit information is concerning how to deal with messages when
they arrive, via some ACL:s, and that's not what I want to do.

Is there some way to have Exim rate-limit the queue runners, so they only
process - let's say 10 messages per minute - for a domain (like
outlook.com/live.com) - _regardless_ of how the message was put in the
queue.

That is, I do not want to rate-limit based on sender-address, sender-ip,
sender-account, sender-<you-name-it>.. I want to swallow EVERYTHING in the
queue that I have already implemented perfect ACL:s for, but then I want
Exim to handle the queue with rate-limiting per outgoing domain.

Is this even possible?

I understand that I can have several exim installations, and bounce stuff
around between them, effectively having one of them "fail" a lot when
trying to push stuff to the other rate-limited one. But this "solution"
seems like a quite nasty work-around - and I would think that the
queue-runner-system itself could have some kind of understanding about
rate-limiting (globally) - since a lot of system nowadays have started
implementing them.

Again, just to make this clear, it should be perfectly OK for 1000 users to
submit 1 message to the same domain, or 1 user to submit 1000 messages to
that domain. Everything ends up in the queue (1000 messages). But _then_ I
would like Exim to only deliver 10 messages each minute to that domain.

PS. All of you who think that stuff shouldn't work this way, it's OK,
you're perfectly welcome to point that out and have your opinion about it,
but that's just not how this system works. ;)

I'll send swedish beer to the one helping me out with this! =)

--
Regards
Charlie Elgholm
Brightly AB