[Solved]I can't receive some emails : Mail delivery failed

[Solved]I can't receive some emails : Mail delivery failed

Some costumers can't send me emails. They receive a message like this:

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. The following address(es) failed:

   xxx@ingeros.com
    host  mx.zoho.com [74.201.155.125]
    SMTP error from remote mail server after end of data:
    554 5.2.3 MailPolicy violation Error delivering to mailboxes

Action: failed
Final-Recipient:  rfc822;xxx@ingeros.com
Status: 5.0.0
Remote-MTA: dns;  mx.zoho.com
Diagnostic-Code: smtp; 554 5.2.3 MailPolicy violation Error delivering to mailboxes
* I replaced the mail address with xxx.