SPF is a Simple Mail Transfer Protocol (SMTP) validation system that verifies the IP address of an email sender. It lets administrators determine which servers can send email messages from a particular domain. SPF alignment with your DMARC policy record is no longer required when you send email from NetSuite. Set up an SPF record only when it is specifically required by a recipient’s email system.
An SPF record is a TXT record using the SPF format with your DNS provider. An SMTP server on the receiving end determines (based on the content of the DNS TXT record) whether the IP address the email message is sent from is approved for that domain.