Email accounts may be prone to being spoofed. (You may also check Email Spoofing for more information about this.) Thus, using SPF records (Send Policy Framework) would help to avoid having this issue since it prevents outgoing spam messages to be sent. Please be guided by this article on how to create it.
Create SPF records via cPanel
Step 1. Login to the cPanel.
Step 2. Under Email panel, click on Authentication.
Step 3. In the Authentication page, look for SPF and click on Enable button since by default this is disabled.
Step 4. You will be redirected to a page where the value for your raw SPF record is shown. Kindly copy the information.
The next time that you will log in to your cPanel, the information will be shown in the SPF field (see image below.)
Please do no hesitate to contact our support team if you have further questions.