What Does "RA" Stand For in the SPF Entry?

The SPF (Sender Policy Framework) record checks the origin and validity of the technical sender address (MAIL FROM address). This address is only used for the SMTP (Simple Mail Transfer Protocol) communication between servers and is not visible to your recipients. 

 "RA" stands for Reporting Address. Reports of SPF abuse will be sent to this address. For more information, click here.