What is this Diagnostic-Code: smtp;550 Blocked

10. August 2012 · Write a comment · Categories: Hotmail, Outlook.com · Tags: , , , ,
When I send e mails to many of my clients the emails do not go thru with this message. Delivery status notification failure. Reporting -MTA:dns;snt0-omc3-s20.snt0.hotmail.com Recieved