I find the soluton for my problem Yahoooooo !!!!,, for which you can avoide the cron job to run every second.Only one line of cron job to clear the open smtp for every one hour or whatever is enough, Let me know if you have done any exercise on this. Or else let me know will tell you how to over come from this problem.
I think that the following configure is proper solution.
./configure --enable-roaming-users=y --enable-tcpserver-file=/home/vpopmail/etc/tcp.smtp --enable-relay-clear-minutes=60
Is this your same solution?
Regards, Yasuyuki Toyoda From Japan, Tokyo