[exim] running two Exim daemons on the same machine

Hello,

I need to run two Exim on a server, mainly due to us wanting
to seperate user's email (no TLS with a self- signed CERT,
keep them seperate, no SA-Exim there). Now, maybe my logic
has holes or I am overseeing something. With two Exim running
I pretty much need two spool directories. Is there any other
way where the 'second' exim just accepts it after checking
and puts it into the same spool of the main Exim? Saves some
headaches, I think, when mails are stuck in the queue, etc.
Would be easier, I think. I may ask a dumb question though, too.

Thanks,
Alexander