Facing issues with my email account

Facing issues with my email account

When sending email to my account the email bounces and gives this error :

Final-Recipient: rfc822;  sawan@eppeok.com
Action: failed
Status: 5.2.3
Remote-MTA: dns;  mx.zoho.com . (204.141.32.121, the server for the domain  eppeok.com .)
Diagnostic-Code: smtp; 554 5.2.3 MailPolicy violation Error delivering to mailboxes
Last-Attempt-Date: Thu, 23 Nov 2017 21:29:49 -0800 (PST)