DMARC Alignment: Why It's Important and How to achieve It

In the fundamental basis of this personalized, individualized solution is an idea known as "DMARC alignment." DMARC alignment (which comes in two flavors: stringent and relaxed) has a significant impact on how strictly your DMARC policy is applied.

But what do these terms really mean? How do they impact the security of your email? And, more crucially, how can you determine which sort of alignment is appropriate for your organization?

DMARC Alignment

DMARC alignment is a method for ensuring that the email sender's identity is consistent and valid throughout all components of the email. It is about matching the domain in the email's "From" address (what the recipient sees) to the information validated by SPF and DKIM. This alignment is critical because it stops malicious actors from leveraging domain name mismatches to bypass email security safeguards. DMARC alignment improves the reliability of your communications by ensuring that the visible domain matches the verified domain.

Alignment develops your DMARC policy by making sure every authentication results match the sender's specified domain. This combination is what makes DMARC effective against email spoofing and phishing. Without it, malevolent senders might easily spoof domains and mislead recipients.

Strict Alignment AND Relaxed Alignment

DMARC alignment is divided into two types: stringent and flexible. Each serves a unique purpose, and recognizing these differences is crucial for developing an effective DMARC policies.

• Strict alignment requires a precise match across domains. This implies the domain in the "From" address has to exactly match the domain certified by SPF and DKIM.
• Relaxed alignment on the other hand, allows for a more flexible matching criteria. For test DMARC to pass, in excess of one of SPF and DKIM must be coordinated.

Why DMARC Alignment Matters

Prevents Email Spoofing

Attackers often impersonate a legitimate domain to trick recipients. Without alignment, an attacker could send an email using your domain, pass SPF or DKIM, and still bypass DMARC. Alignment ensures that only senders explicitly authorized by your domain can pass authentication.

Protects Brand Reputation

If someone spoofs your domain, your customers could fall for phishing emails that seem to come from you. DMARC alignment prevents that, building trust and maintaining your brand's integrity.

Improves accessibility to emails.

Mail providers such as Gmail, Yahoo, and Microsoft prefer domains that use DMARC with proper alignment. This can result in improved inbox placement and fewer emails.

How DMARC Alignment Is Achieved

Understanding how your emails are sent and properly configuring your SPF and DKIM records are key to achieving alignment. Here's how to accomplish it:

Step 1: Examine your "From" domain first.

Examine the "From" domain that is utilized in your outgoing emails first. This is the domain that has to match DKIM or SPF.

Step 2: Set up SPF for Alignment

Make certain that:

You have updated the SPF record for your domain to include all valid transmitting IPs.

Step 3: Establish DKIM Signing

Make sure your signature on DKIM is signed by the domain that the "From" address is associated with, or signed by a subdomain that, in the case of relaxed alignment, has the same organizational domain.

The d= element in the DKIM header needs to match the "From" domain in order for DKIM alignment to occur.

Step 4: Publish a DMARC Record

The DNS hosting company for your domain creates and publishes a DMARC record.

Step 5: Track and Modify

To find out who is sending mail on your behalf, use DMARC reports. As you make sure that all valid senders are in agreement, gradually transition from p=none (monitoring) to quarantine or refuse.

The Framework for DMARC

Naturally, DMARC offers more advantages than only alignment; it provides a thorough framework for email security.

• Authentication: Uses alignment checks, DKIM, and SPF to make sure emails are authentic.
• Reporting: Offers two report formats for tracking and controlling email authentication.
• Aggregate Reports: Compile the results of email authentication, such as IP addresses, SPF/DKIM results, and email delivery status.
• Failure Reports: Provide thorough information about specific emails that don't pass DMARC checks (limited support because of privacy issues).
• Conformance: Domain owners can provide a DMARC policy (p=none, p=quarantine, or p=reject) for addressing emails that don't pass DMARC checks.

Frequent Asked Questions

1. In DMARC, what distinguishes DKIM alignment from SPF alignment?

SPF alignment:

The From: header domain and the domain in the Return-Path (envelope from) must match.

DKIM alignment:

The From: header domain and the domain in the DKIM d= tag need to line up. SPF or DKIM must both pass and be in alignment for DMARC to pass.

2. What are the practical meanings of "relaxed" and "strict" alignment?

Relaxed: It is believed that sub.example.com and example.com are aligned.

Strict: There are no subdomains that match example.com.

In your DMARC policy, you select alignment mode (most use relaxed by default).

3. Why does my DMARC fail when my DKIM or SPF passes?

Alignment is necessary for DMARC. If SPF is successful, but alignment is unsuccessful since it employs a third-party sender (such as mail.sendgrid.net) and the From domain is example.com. Unless you have custom domain signing or are utilizing a subdomain method, alignment fails when DKIM is signed by a domain like bounce.mailchimpapp.net and From: is example.com.

4. Is it better to use strict or relaxed alignment?

For compatibility, relaxed is usually advised, particularly when utilizing third-party services. Strict provides better security, but unless infrastructure is closely monitored, it may result in more DMARC failures.