I need to sent email to user with attached document as .zip file using PHPMailer with ZOHO SMTP. I am getting the following errors and unable to send email with attachment.

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.

phpcodehub@gmail.com , ERROR_CODE :552, ERROR_CODE :5.7.0 This message was blocked because its content presents a potential
                        5.7.0 security issue. Please visit
                        5.7.0   https://support.google.com/mail/?p=BlockedMessage  to review our
                        5.7.0 message content and attachment content guidelines. e185si10746942oia.202 - gsmtp

naveenrbit@gmail.com , ERROR_CODE :552, ERROR_CODE :5.7.0 This message was blocked because its content presents a potential
                        5.7.0 security issue. Please visit
                        5.7.0   https://support.google.com/mail/?p=BlockedMessage  to review our
                        5.7.0 message content and attachment content guidelines. e185si10746942oia.202 - gsmtp



  Return-Path:query@phpcodehub.co.in
 Received:from localhost (106.51.141.245 [106.51.141.245]) by  mx.zohomail.com
        with SMTPS id 1499071482464623. 1697517219561; Mon, 3 Jul 2017 01:44:42 -0700 (PDT)
 Message-ID:< 42f14afeae223734afa953f6321548 2b@localhost>
 Date:Mon, 3 Jul 2017 08:44:36 +0000
 From:phpcodehub < query@phpcodehub.co.in >
  To:naveenrbit@gmail.com
 Subject: phpcodehub.co.in  : article source code
 Content-Type:multipart/mixed;
        boundary="b1_ 42f14afeae223734afa953f6321548 2b"

Since I can sent email without attachment, can you please help me to solve this issue.