Why use SPF, DKIM, and DMARC?
SPF is used to restrict which mail servers can send email for a specific domain name. This framework is designed to detect and block email spoofing. When signing outgoing messages with DKIM the recipient will be able to verify the respective message is from the sender it claims to be from and that its content has not been modified. When you apply DKIM it reduces the chances of emails being identified as spam and helps discourage others from spoofing your email, especially when combined with SPF. DMARC is an email protocol designed to help prevent email spoofing when used in conjunction with SPF or DKIM.
How do SPF, DKIM, and DMARC work?
SPF’s framework provides a mechanism to allow receiving mail exchangers to verify that incoming mail from a domain comes from an IP address authorized by that domain’s administrators. The list of authorized sending hosts and IP addresses for a domain is published in the DNS records in the form of an SPF record, which is a specially formatted TEXT record.
DKIM adds a special signature to the email headers. This signature contains a hashed value of the content (both important headers and the body). When a server that is checking for DKIM receives an email it will retrieve the public key from the DNS of the sending domain then use the key to decrypt the signature and verify the content.
As mentioned, DMARC is an email protocol that should be used in conjunction with SPF or DKIM. It gives the administrator of the receiving server the ability to act on messages when the criteria are not met. DMARC also provides the tools for senders to monitor the abuse of their domains.
Help prevent spoofing with SolarWinds Mail Assure
SolarWinds® Mail Assure is a cloud-based email security solution with advanced threat protection that guards inbound and outbound email from email-borne threats. Real-time pattern threat recognition leverages a variety of filtering technologies including anti-phishing and impersonation protection. Finally, Mail Assure’s technology supports SPF, DKIM, and DMARC, enabling customers to take every measure possible to help prevent email spoofing and phishing attacks.
To experience how SolarWinds Mail Assure can help protect your inboxes from cyber threats, start a trial today.
Mia Thompson is product marketing manager, Mail Assure, at SolarWinds MSP.