Email authentication - Gmail Help. Email authentication is a way to ensure that an email provider will be able to recognize the sender of an incoming message and fight spam and abuse.
You can use authentication data to verify the source of any message that you receive. For example, if you receive a message from a big sender (like a financial institution, or a major email provider, like Google, Yahoo or Hotmail) that isn’t authenticated, this message is most likely forged and you should be careful about replying to it or opening any attachments. SPF specifies which hosts are allowed to send messages from a given domain by creating an SPF record.
You can publish an SPF record here. DKIM allows the sender to electronically sign legitimate emails in a way that can be verified by recipients using a public-key. DomainKeys Identified Mail (DKIM) About SPF records - Google Apps Administrator Help. We recommend that you create a Sender Policy Framework (SPF) record for your domain.
An SPF record is a type of Domain Name Service (DNS) record that identifies which mail servers are permitted to send email on behalf of your domain. The purpose of an SPF record is to prevent spammers from sending messages with forged From addresses at your domain. DMARC.org - Domain-based Message Authentication, Reporting and Conformance.