Hi, recently I sent 2 emails to my daughter in Australia via her Hotmail account but I received messages from *** Email address is removed for privacy *** as follow:

"Delivery has failed to these recipients or Groups: 

xxxxxxxxx@yahoo.com - ???????????

A communication failure occurred during the delivery of this message. Please try to resend the message later. If the problem continues, contact your helpdesk."

I am wondering why it quoted as Yahoo.com instead Hotmail.com?   Furthermore, I telephone to my daughter and she told me that she has actually received that 2 emails I've sent.   Thus, this Postmaster message really annoying me and also makes me feel unsecured whether my mails actually reach the recipient.

I would be grateful if someone can help and advise me how to solve the problem.  

Many thanks in advance.

Steve from SG.