(urgent issue) Error sending email: Domain Not Resolved

Hi Sir,

We got sending issue as following. Could you advise it ?

From : < mailer-daemon@mail.zoho.com>
To : < jennyz@lemon247.com>
Date : Thu, 19 Nov 2015 14:02:16 -0500
Subject : Undelivered Mail Returned to Sender
============ Forwarded message ============

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.

MFrankowski@wvschools.ca Domain Not Resolved

Received:from mail.zoho.com by mx.zohomail.com
with SMTP id 1447959690768753.3178893676218; Thu, 19 Nov 2015 11:01:30 -0800 (PST)
Message-ID:<151211f7dbf.b8250 cd11078569.7363125360528006917@lemon247.com>
Date:Thu, 19 Nov 2015 14:01:30 -0500