What is "persistent transient failure: delivery time expired?

I sent a message on hotmail to someone, and keep getting delivery failure notice. Did they block me?

• Alright so, I sent this email to some one on hotmail and each time I do I get this 'delivery failure' notice say it couldn't send the message. On the failure notice it gives the time/date/ and who I sent it to. And then it gives an attachment on the email with the sent emails subject as a name. Anyway, its always the same person which it does not get sent to-- do you think they blocked or deleted me? If I send the same email to myself or anyone else its fine. Oh and I cans till see the persons profile picture, and friends and its says im connected with them

• Answer:

  I don't think so, those free email services are rubbish and that happens with them, you'd be better buying a domain for yourself.