Milter-greylist

> I understand that sleep(3) will put the whole process to sleep, which
> makes the milter unable to process other requests from sendmail.
> sched_yield(3) seems to be the right way. Could you investigate?
> 

At least on Tru64 this is in the man page of sleep (3):

  In a multi-threaded environment, the sleep() function is redefined so that
  only the calling thread is suspended.

Best,
Attila