The reason for the bounce backs are due to Google that has upgraded their security, Which would now require your records to be compatible. In this article we will show you how to update the specific record to eliminate this issue

Step 1. Log into Cpanel

Step 2. Click on Zone editor

Step 3. Click on Manage

Step 4. Click on TXT

Step 5. Click on Edit

Step 6. You can then add the standard SPF record and click save after

NOTE: If an SPF record already exist you can replace it with the record below 

v=spf1 a mx ~all