[exim] routing defer (-55): domain is in queue_domains

Hi

For some reason today im seeing a lot of
routing defer (-55): domain is in queue_domains.

Ive browses the Exim archive etc, and from what I gather.
This aint a bad thing.
My understanding is that exim will try at a later stage.
But my question is, under what condition will this type of message appear.

I only have 15 users that use this mailserver, and I smarthost my mail to my
isp.
Therefore there is no DNS lookup etc.
Yesterday I installed clam antiv, but this was all working perfectly
yesterday, and I dont have any other servers etc running, except for a
crontab entry for fetchmail.

My linux distro is Debian, would anyone know where I can find the script etc
that runs the
exim queue command.
I have looked at my crontab and cron.daily etc, but I cant see to find it.

Any assistants or explaination etc would greatly be apprected.

Kind Regards
Brent Clark