Sender Policy Framework (SPF) records let you specify which servers are permitted to send email on behalf of your domain (i.e. using firstname.lastname@example.org“From” address).
If you’re using Relenta mail.relenta.net SMTP server to send email from your Relenta account, we strongly encourage you to publish SPF records for your domain. This way your recipient’s servers or ISP will be able to check your SPF record to make sure you’ve authorized Relenta servers to send email on your behalf.
To set your domain’s SPF record, you must have access to your domain’s DNS settings (usually via your web-hosting control panel). On your DNS resource, publish the following text record:
v=spf1 include:spf.relenta.com ~all