tail -f /var/log/maillog
..

Each 1 minute it repeats!!!!

2001-10-06 23:22:13 15q6OD-00086h-00 <= nobody@shockwave.com H=outbound.shockwave.com [63.99.128.25] P=esmtp S=950 id=20011007052222.5E407792@mcfeely.shockwave.com

What is this?