Mail Delivery Status Notification (Delay) - "The following addresses had fatal errors"

Hello,

I keep receiving this message when sending emails, including recipients with which I had no problem communicating in the past:

eceived: from mail.zoho.com by mx.zohomail.com
	with SMTP id 1470027651718363.64947134444753; Sun, 31 Jul 2016 22:00:51 -0700 (PDT)
Date: Mon, 01 Aug 2016 12:00:51 +0700
From: xxxx@hoianvillagevillas.com&gt;
To: &lt;xxxx@hoianexpress.com.vn&gt;
Message-ID: &lt;1564479da54.10ea7270a55787.8223829241330417701@hoianvillagevillas.com&gt;
Subject: dang thu mail
MIME-Version: 1.0
Content-Type: multipart/alternative; 
	boundary="----=_Part_127966_453820127.1470027651669"
X-Priority: Medium
User-Agent: Zoho Mail
X-Mailer: Zoho Mail

Let me know what could be the solution to this problem. Thank you.