I found this in my log server:
sm-mta[11410]: r9BKb6YY021119: to=<
[email protected]>, ctladdr=<
[email protected]> (33/33), delay=2+07:24:18, xdelay=00:00:01, mailer=esmtp, pri=29911032, relay=mail1.mkuku.com. [58.22.50.83], dsn=4.0.0, stat=Deferred: Connection refused by mail1.mkuku.com.
This message is repeated every 10-30 seconds with a different "to" address.
What is this? Is my server being used to send spam?