Email account send but not receive

Email account send but not receive

Good day.
The e- mail account and ricardo@rinaldiarquitetura.com.br contato@grupoatitude.com.br send emails normally. However, from time to time do not receive emails. The various senders receive a statement like this:

"
Technical details of permanent failure:
Google tried to deliver your message , but it was rejected by the server for the recipient domain grupoatitude.com.br bymx.zohomail.com . [ 74,201,154,201 ] .

The error que the other server returned was :
554 5.2.3 MailPolicy Violation Error delivering to mailboxes .
"

What is happening ? How to eliminate this problem ?
thank you ,
Vanius