DMARC-Domain-based Message Authentication, Reporting and Conformance is an open email authentication standard that sending domains use to block fraudulent emails. DMARC is built on top of two earlier standards – SPF and DKIM and adds additional features like reporting, policy definition, and the notion of identity alignment. For more information checkout DMARC
If implemented properly, DMARC will completely stop phishing attacks in which an intruder sends an email with a' From' address that appears to come from a secure domain. As this is the primary form of a phishing attack, DMARC is a very powerful tool to protect enterprises against phishing.
DMARC adds three key elements to the current email authentication standards:
Reporting: DMARC-participating receivers decide to provide email encryption documents to submit domains. It helps holders of these receiving domains to understand the current state of their domain's email encryption, to see valid sites that may not be properly authenticated, and to find sources of domain abuse.
Policy: For DMARC, receiving domains will decide how the recipient can treat an email that refuses to authenticate, rather than leaving it to the discretion of the receiver. It requires domains to authenticate their legitimate email addresses over time, rather than asking domain holders to address all authentication problems instantly.
Report only' p= none ' rule may be helpful during this investigative process, but domain holders will aim to meet the' p= quarantine' or' p= reject' standard.
DMARC aims to remove unauthorized email from the network of an individual used in phishing attacks and other forms of cybercrime.DMARC helps orgainzations to prevent harm to integrity that happens when a domain is effectively used in a phishing scheme.
DMARC defines three policy levels that describe how receivers are supposed to handle email failing authentication. These levels are ‘p=none’, ‘p=quarantine’, and ‘p=reject’.
none: Receivers are instructed to not change how they deliver email based on email authentication failures. The ‘none’ level is typically used when a domain owner is in the initial process of authenticating their email services; moving beyond this level is key to enable DMARC to stop fraud.
quarantine: Receivers are asked to mark messages failing authentication as spam.
reject: Receivers are requested to block messages failing authentication entirely, and not deliver them to their intended recipients.
DMARC can help to successfully prevent direct domain spoofing, where attackers use an organization's exact domain name in the “from” address within an email. Nevertheless, DMARC can not prevent look-alike domain spoofing once hackers use a domain name that is a slightly modified copy of a legal domain. DMARC can not provide coverage against newly registered domains that are often used to launch attacks for several hours or days before being shut down. For these purposes, many companies opt for a multi-layer solution to email protection which utilizes DMARC in combination with a number of other protections.
DMARC is all about checking that the email in the' From' header is the real recipient of the message. To do this, the software parameters used to validate the senders are DKIM and SPF. Nevertheless, both DKIM and SPF do not need either DKIM or SPF to match the From header and user identification. Alignment ensures that these domains will align when configured properly.
Sender Policy Framework (SPF) is a free, DNS-based email encryption system that enables domain senders to specify which IP addresses are allowed to send email to receiving mail servers on behalf of the domain. For more information checkout SPF