I noticed that for some reason, sendmail is blocking inbound
my email messages, in particular users from hotmail.com

I am able to send email as a user on my email-server but
apparently I am unable to send email to my email server
from the Internet such as from hotmail.com.

>From maillog, I got:
============
Mar 31 19:12:02 <hostname> sendmail[12669]: ruleset=check_relay, arg1=blu139-omc3-s11.blu139.hotmail.com, arg2=127.0.0.2, relay=blu139-omc3-s11.blu139.hotmail.com [65.55.175.211], reject=553 5.3.0 Rejected due to Open Relay see http://www.ordb.org/lookup/?host= for more information

It says above to look at http://www.ordb.org/... and I tried to but apparently it seems that
this site is not accessible?

Can someone tell me what might be going on?
And where is this site entry located in my sendmail configuration files?

Thanks!