Hello, how are you!?

Everytime I try to send e-mails using my zoho account, it does not work properly and the system shows me the under mentioned information:

I must say that it happened to several e-mails adresses that I have tried to send.

"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 

[<marciorafael@gmail.com>] 


Received:from 172.29.249.242 (172.29.249.242 [172.29.249.242]) by mx.zohomail.com 
    with SMTP id 1262017506989281.4446743712697; Mon, 28 Dec 2009 08:25:06 -0800 (PST) 
Message-ID:<125d61aedee.-7336975778791368952.6928913134903592005@zoho.com> 
Date:Mon, 28 Dec 2009 08:25:06 -0800 
From:Márcio Rafael Oliveira <marciorafael@zoho.com> 
User-Agent:Zoho Mail 
To:"Marcio" <marciorafael@gmail.com> 
Subject:Teste! 
Content-Type:multipart/mixed; 
    boundary="----=_Part_586_1913639936.1262017506797"from 172.29.249.242 (172.29.249.242 [172.29.249.242]) by mx.zohomail.com 
    with SMTP id 1262017506989281.4446743712697; Mon, 28 Dec 2009 08:25:06 -0800 (PST)" 

Can you help me out to solve this problem so I can use it properly!?

Thanks for the patience!

Márcio Rafael