Mail Delivery Failure

[Mail Delivery System]

This message was created automatically by the mail system (ecelerity).

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

>>> adetoyin02 at yyahoo.com (while not connected): 550 5.4.4 [internal] NULL MX domain does not accept mail
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