We keep getting bounce backs or mail undelivered messages on some domains

We keep getting bounce backs or mail undelivered messages on some domains

Here is the email message back from zoho.

Subject: Mail Delivery Status Notification (Delay)

Subject: Mail Delivery Status Notification (Delay)
Date: Mon, 20 Jun 2016 19:03:51 -0700
Content-Type: text/plain;
boundary="----=_Part_167220_56491845.1466474631241"; charset="utf-8"
Content-Transfer-Encoding: quoted-printable
X-Mailer: Zoho Mail
Thread-Index: AQJN8OxfbJa7+y5ORRI24ALY4CFFxA==
MIME-Version: 1.0

This message was created automatically by mail delivery system.

THIS IS A WARNING MESSAGE ONLY.

YOU DO NOT NEED TO RESEND YOUR MESSAGE.

The original message was received at Mon, 20 Jun 2016 19:03:51 -0700

    ----- The following addresses had fatal errors -----   =20
   [Status: DOMAIN_NOT_RESOLVED, Address: < arnold.anisgarten@cohenreznick.c=
om>]

Message will be retried for 4 more day(s)

    ----- Transcript of session follows -----   =20

 Received:from KarimDell (cpe-45-49-225-10.socal.res.rr.com [45.49.225.10])=
 by mx.zohomail.com
with SMTPS id 1466472825530282.7657262227583; Mon, 20 Jun 2016 18:33:45 -0=
700 (PDT)
 Message-ID:<011d01d1cb5c$eb8f93a0$c2aebae0$@dynamicscapital.com>
 Date:Mon, 20 Jun 2016 18:33:30 -0700
 From:"Karim Jaude" < karim@dynamicscapital.com>
 Subject:Potential Investment
 Content-Type:multipart/mixed;
boundary=3D"----=3D_NextPart_000_011E_01D1CB22.3F31CD10"