First of all make sure that, your Business Email Services is active.

Step 1: Login to your Client Area and Click on View Details of your purchased Business Email Product

Step 2:  Then, Page Scroll down to CloudMail DNS Records as below

Find the CloudMail DNS Records, and add them to the Domain Name as DNS Resource Records.

If you have a cPanel or Plesk Hosting Service with us, You can update our Hosting Nameservers to your domain registrar and Manage your DNS through Plesk or cPanel.

Configure DNS Records :

Example 1 of Add Mail Record

Example 2 of Add SPF Record

After that login to CloudMail, check the Email Deliverybility thorough the cPanel

Then click Manage and collect records that problems Exist.

DMARK Settings