What is SPF (Sender Policy Framework)?
It’s first important to note that not all servers check whether a domain has SPF set up, however if they do, most servers will either mark e-mail sent as spam or automatically delete it if a server sends an e-mail when they are not authorized to do so for the e-mail address they are purportedly sending from, if there is an SPF record set up against the domain in question restricting what server IP addresses are authorized to send e-mails for the specific domain name.
For example, if your domain was example.com, and your domain is hosted on one server and all e-mails from your domain are sent by the same server, your SPF record would restrict legitimate e-mails to that server IP address only. And so any servers that check the Sender Policy Framework entry for e-mails received will either reject or mark as spam, any e-mails that are sent by servers not authorised as per the SPF entry.
How do I set up SPF for my domain?
It’s incredibly easy. Log in to your WHUK cPanel Hosting control panel and go to the Email Authentication section. From here you can add other IP addresses in the “Additional Ip blocks for your domains” section. If you do not have WHUK cPanel Hosting, most web hosting providers will likely have an SPF record set up for you when your web hosting account was set up, and in this case, SPF would be set up in the “Email Authentication” section; but I would recommend you check it nonetheless to make sure.