It runq eventually gives up, the sender should be notified via email.  Is
that what you are asking for?

The last thing runq does before removing the file is sending an error
email to the sender.  Can you actually send email to
ar.aichi-u.ac.jp!arisawa on the system in question?  Do you
see anything in /sys/log/mail at the same time as the
	ar Nov 10 11:50:32 removing none/C.004414
in the runq log?