Span - relaylock: /var/qmail/bin/relaylock

[javisan43]

I've been several days with attacks from multiple IP.
I reviewed the logs (maillog) and Ip that reflects is that really sends.
Is there a way to see the real IP and stop this attack?
Submit a few records maillog to see this kind of attack.
Cocuments and SettingsPacoEscritoriomaillog/150786: Oct 4 19:35:16 venalsur relaylock: /var/qmail/bin/relaylock: mail from 86.101.81.107:9221 (catv-86-101-81-107.catv.broadband.hu)
Cocuments and SettingsPacoEscritoriomaillog/150861: Oct 4 19:35:39 venalsur relaylock: /var/qmail/bin/relaylock: mail from 88.250.174.247:16868 (dsl88-250-44791.ttnet.net.tr)
Cocuments and SettingsPacoEscritoriomaillog/150905: Oct 4 19:35:59 venalsur relaylock: /var/qmail/bin/relaylock: mail from 65.48.189.248:4888 (mail.venalsur.es)
Cocuments and SettingsPacoEscritoriomaillog/150930: Oct 4 19:36:16 venalsur relaylock: /var/qmail/bin/relaylock: mail from 80.160.76.197:39109 (fep33.mail.dk)
Any idea as to this attack? - I use plesk 4.0

 

[breun]

These are perfectly normal (and usually meaningless) log messages. And what is not real about these IP addresses?