[exim] prevent received mail from being queued

I'm sitting behind a DSL line and retrieve my mail with fetchmail
which forwards it to exim4. Usually, incoming mail is delivered
immediately. But if more than about 10 mails have queued up, only
a couple of them are delivered and the rest remains in the queue
up to the next queue run. The only queue related settings I can
find in /etc/exim4/exim4.conf.template are

queue_domains = ! +local_domains
queue_smtp_domains = +local_domains
queue_list_requires_admin = false

The system is completely idle when doing this, so I don't think I
is related to a load maximum or something lika that.

P.S.: Please CC me, I'm not yet subscribed to the list.

Ciao

Dominik ^_^ ^_^

--
Dominik Vogt, dominik.vogt@???