DMARC :
Domain-based Message Authentication, Reporting and Conformance (DMARC) is an email security protocol that authenticates email senders and helps to prevent email spoofing. DMARC builds on the SPF and DKIM protocols and adds a mechanism for receiving servers to provide feedback to the sender about whether or not email from the sender’s domain is being delivered successfully. DMARC also helps to prevent email spoofing by specifying how email should be handled if it fails SPF and DKIM authentication.
SPF :
Sender Policy Framework (SPF) is an email security protocol that authenticates email senders by verifying that email coming from a given domain is authorized by that domain’s administrators. SPF is a DNS text entry that specifies which mail servers are authorized to send email on behalf of a domain.
DKIM :
DomainKeys Identified Mail (DKIM) is a security protocol that authenticates email senders by verifying that email coming from a given domain is authorized by that domain’s administrators. DKIM uses cryptographic signatures and public-key cryptography to verify that an email message has not been tampered with and that the sender is authorized to send email on behalf of the domain.
FROGED