Unable to send mail - HELP

Unable to send mail - HELP

Hi guys,


Can you guys help me out? Was receiving "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.


554 5.2.3 MailPolicy violation Error delivering to mailboxes" whenever i tried mailing.

Pls advice what to be done.

Thanks.
balram_spg@zoho.com