Error, ERROR_CODE :550, ERROR_CODE :5.7.1 Command rejected

Error, ERROR_CODE :550, ERROR_CODE :5.7.1 Command rejected

Hi there,

I am attempting to send to a particular address, but am receiving this bounce error. Any ideas on what could be going on?

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its recipients. This is a permanent error.


email@domain.com Error, ERROR_CODE :550, ERROR_CODE :5.7.1 Command rejected



Received:from [ip] (d[ip]) by mx.zohomail.com

with SMTPS id 1429292337055690.2171628188966; Fri, 17 Apr 2015 10:38:57 -0700 (PDT)

Message-ID:<email@domain.com>

Date:Fri, 17 Apr 2015 10:38:53 -0700

From:

User-Agent:Microsoft-MacOutlook/14.4.8.150116

To: 

Subject:Incoming test

Content-Type:multipart/mixed;

boundary="B_3512111936_15128884"




Many thanks!