Set Up SPF Records
When you add SPF information to your DNS records, you are able to specify the email servers you use to send email from your domain. This validates your sending email address, which can improve your email deliverability rate. In other words, SPF helps to keep your domain’s email out of your recipients’ spam folders.
To get started, you must first contact your DNS hosting company and ask them to add the following SPF information to your DNS records. Or, if you can log into the control panel for your DNS, you can make this change yourself.
v=spf1 [any combination of the below] ~all
Hosted Exchange and Email Hosting customers:
If you send email from your own server (replace "184.108.40.206" with your mail server IP):
For example, if your domain falls into both of these categories, the SPF would look like the following:
v=spf1 include:emailsrvr.com ip4:220.127.116.11 ~all
Repeat these steps for every domain from which you plan to send email.
Note: When you are composing an email, you must use a "From" address (or, specifically, a "Return-Path") that belongs to an SPF-enabled domain, otherwise SPF will not be in effect.