Thanks for your reply. i changed it to
exec /usr/local/bin/tcpserver -c 2000 -l 0 -R -H -v 0 110 \
exec /usr/local/bin/tcpserver -c 2000 -t 50 -l 0 -R -H -v 0 110 \
yesterday and restart pop3d but the "file busy" problem still there.
while i'm guessing at this point that the issue is something other than the tcpserver invocation, you might try
1. reduce the -c value to something more realistic, like 200 instead of 2000
2. remove the -v option
3. add -D