[exim] delay mail delivery from specific senders

Dear All,

Exim is running as:
queue all mail, and then run a mail queue flushing process every 10 minutes,
all working good

now i have a request sending out message only FROM specific user without
queuing
for instance: when user@??? will send outside email exim will deliver
it immediately, but all other emails will go to queue for 10 minutes.
how can it be done, any ideas?

i found Exim is powelfull and i want to use it as my Email Gateway.
Thanks in advance for your help!!

konddor