Response "Fwd: failure notice"

[Andriy Babiy]

On every message, sent to the list, I receive a strange response with the 
subject line: "Fwd: failure notice".
The body contains:
===> BODY BEGIN
Hi. This is the deliver program at eyou.com.<br>
            I'm afraid I wasn't able to deliver your message to the 
following addresses.<br>
            This is a permanent error; I've given up. Sorry it didn't work 
out.<br><br>

kugua065315 at 163.com<br>

550 MI:SPF mx18,wKjR47Dr_AisCDNGl+65Ow==.9315S2 1177749676 
http://mail.163.com/help/help_spam_16.htm
<br>

--- Attachment is a copy of the message.<br><br>
<snip>
_______________________________________________
freebsd-questions at freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-questions
To unsubscribe, send any mail 
to "freebsd-questions-unsubscribe at freebsd.org"
===> BODY END

Sure, I know nothing about eyou.com and kugua065315 at 163.com.
My message appears on the list, so it is delivered.
What does this response mean? Could anyone explain me why I get this 
response?
Thank you in advance.

Andriy