Procedure:
Step 01: In your control panel, click on Domains and then on the domain name in question.
Step 02: Now click on “Edit DNS zone records”.
Step 03: First, delete the default TXT record by clicking the Red X to the
right on the respective row.
Step 04: Add the following SPF record to your DNS zone.
Step 05: Click Add record, pick TXT from the drop-down box, copy/paste the
record into the Record Data field v=spf1 include:zcsend.net ~all