hotmail.com live.com admin needed

[cperez at runcentral.com (Carlos M. Perez)]

Hi,

We're trying to resolve some delivery issues reported by hotmail users.  
Started happening a few weeks ago.  Getting immediate NDRs, and the 
server that is supposed to receive the email has no records of 
attempts.  The messages also don't match what the receiving server 
should be sending.  The server(s) listed in the MX should receive all 
email without authentication, since it's a mail filtering service (Maxmail)

===
Reporting-MTA: dns;snt0-omc3-s27.snt0.hotmail.com
Received-From-MTA: dns;SNT133-W53
Arrival-Date: Mon, 22 Oct 2012 14:09:49 -0700

Final-Recipient: rfc822;administrator at xxxx.com
Action: failed
Status: 5.5.0
Diagnostic-Code: smtp;550 authentication required
===

Kindly contact me off-list.

Thanks,

-- 
Carlos M. Perez
Runcentral, LLC