From your hosting cPanel account you can enable the DKIM (Domain Keys Identified Email) and SPF (Sender Policy Framework) authentication. This will help verify that email comes from a trusted sender. You can do this from your cPanel account and then adding them respectivly as DNS records to your domains to work.
Login to the cPanel account > Email > select the ‘Authentication icon’ > new window will open and here you can see the options to enable SPF and DKIM records > Click ‘Enable’ and the records will be added to the DNS zone. See here.
