Why Do You Need a Strong DMARC Policy to Authenticate Emails?

The DMARC policy of a sending domain may be the most misunderstood and underused aspect of email authentication. It’s also a strong tool for preventing email spoofing, which protects your subscribers and your brand’s reputation in the longer term.

The difficulty is that this specification’s adoption has been slow, and too many DMARC policies have weak settings, preventing businesses from realizing its full benefits.

Let’s take a look at how to deconstruct DMARC so you can get the most out of it.

The basics of DMARC

Domain-based Message Authentication, Reporting, and Conformance is the term for Domain-based Message Authentication, Reporting, and Conformance. Its major goal is to ensure that SPF (Sender Policy Framework) and DKIM are in sync (Domainkeys Identified Mail). Receiving mail servers use the DMARC policy to decide whether or not to send messages and how to properly filter them.

To explain email authentication protocols briefly:

• SPF is a list of hostnames and IP addresses published on your DNS that are approved to send mail for your domain.
• DKIM involves an encrypted digital signature or private key that matches a public key on a domain’s DNS.

Both these protocols help validate messages and prevent forged emails from reaching the inbox. A DMARC policy sits on top of SPF and DKIM, combining the two for stronger authentication.

Imagine DMARC as the bouncer at an exclusive party: SPF is like the list of approved guests and DKIM is a VIP pass. If you aren’t on the list or don’t have the pass, you don’t get into the inbox.

The benefits of DMARC

For mailbox providers … DMARC provides information about how to filter messages that fail authentication. This is your domain’s DMARC policy. When mailbox providers are unclear how to handle unauthenticated messages, they may lean towards delivering them. That’s because recipients are often more upset about not receiving real emails than dealing with spam.

For email recipients … DMARC makes the inbox a safer place because it prevents malicious phishing emails from getting delivered. Specifically, it stops emails with forged information in the “from” field of an email header.

For senders … DMARC also provides valuable reports on the IP addresses that are sending mail on behalf of your domain. This lets you monitor for brand spoofing and find out if legitimate emails are encountering authentication issues that impact deliverability.

You can set up DMARC so that you get daily reports from servers receiving any emails claiming to be from you. These reports are critical to successfully using DMARC to protect your email reputation. They tell you every source sending emails on your behalf and allow you to separate unauthorized sources from legitimate ones.

All major mailbox providers support DMARC. That includes Gmail, Outlook, Yahoo, Apple Mail, and AOL. In fact, implementing DMARC is a signal to these providers that you’re a responsible and reputable sender they can trust.

What is a DMARC policy?

The most important component of your DMARC record is your company’s DMARC policy. It’s a TXT record in your hosting provider’s DNS settings, many as SPF and DKIM.

When it comes to configuring your DMARC policy in the record, you’ll have one of three options which are reflected in the “p=” value.

p=none: This tells mailbox providers to take no action on emails that fail authentication. They will most likely be delivered.

p=quarantine: This policy informs mailbox providers to send emails that fail authentication to spam or junk folders. These messages may also be blocked.

p=reject: This is the strongest DMARC policy value. It ensures all malicious email is stopped dead in its tracks.