Yes, we support SPF.
You can enable SPF in cPanel. Please see Related Articles for more information.
Additionally, Done5 Technology can add a custom SPF record to your DNS zone. If you need further assistance, please open a support ticket with our Guru Crew on the Customer Portal at https://done5.com/clients/submitticket.php. Make sure that you specify in the ticket the exact lines that you want to add to your zone file.