[Exim] rsmtp: to many processes

Hi,

I get my mails per uucp. Uucp invokes rsmtp with the mail batchesa and
exim delivers the mails, but not with $queue_run_max processes. Exim runs
1 Process for 1 e-mail. And at me many mails are send to inn, so exim
invokes mailpost, and the load rises very fast until exim dies on a load
of 10.

How can I prevent this? Why exim call 1 Process for 1 e-mail?

Joerg.