[Exim] best way of feeding lots of mails into exim?

Hey all!

happy new year first of all!! (ok... I'm a bit late ;))


I've written a mailinglist type of program, that creates one mail per
subscriber.
I currently feed this into exim using exim -bS (so.... local SMTP).

I was wondering whether there is a better (ie. faster) way of feeding them
into exim. The system quite often runs out of open files using this so......


Thanks for your help!

Philipp