554 5.2.3 MailPolicy violation Error delivering to mailboxes

554 5.2.3 MailPolicy violation Error delivering to mailboxes

hi
i have an issue , one of my client mailed me some attachements and the email was bounced with the following message

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The response from the remote server was:

554 5.2.3 MailPolicy violation Error delivering to mailboxes


Final-Recipient: rfc822; info@ichibannepal.com
Action: failed
Status: 5.2.3
Remote-MTA: dns; mx.zoho.com. (204.141.32.121, the server for the domain ichibannepal.com.)
Diagnostic-Code: smtp; 554 5.2.3 MailPolicy violation Error delivering to mailboxes
Last-Attempt-Date: Thu, 09 Feb 2017 03:04:39 -0800 (PST)

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When i asked him to send a blank test mail i received the email , can you please find out what the issue was ....


Thank you