DMARC Policy Optimization: Protecting Your Brand and Boosting Email Deliverability

How to Stop Email Spoofing Without Losing Legitimate Mail

If you’re a marketing expert managing your brand’s emails, there’s a good chance you’ve heard of DMARC — especially if someone warned you about email spoofing, spam complaints, or the need for BIMI and better deliverability. But for many, DMARC is still a mystery. It shows up as a weird-looking TXT record in your domain settings. If you’ve seen something like this…

v=DMARC1; p=none; rua=mailto:dmarc-reports@yourdomain.com

… and weren’t quite sure what it does, this article is for you.

Let’s break it all down — in simple wording — and then show you how to optimize your DMARC policy for security, brand reputation, and email performance.

DMARC builds on two older email authentication methods:

• SPF (Sender Policy Framework): Defines which servers are allowed to send mail on behalf of your domain.
• DKIM (DomainKeys Identified Mail): Adds a digital signature to your email headers to verify the message wasn’t altered.

DMARC adds the final layer: policy enforcement and reporting.

Why You Need DMARC?

• Prevent Spoofing: It stops bad actors from sending fake emails using your domain (like phishing or scams).
• Protect Your Brand: If someone uses your domain for fraud, it can damage your brand reputation.
• Email Deliverability: Email providers favor authenticated emails — DMARC helps your legit emails land in the inbox.
• Enable BIMI: Want your logo to show next to your emails in Gmail or Yahoo? You must have a strong DMARC policy (with enforcement).

Anatomy of a DMARC Record

A DMARC record is a single line of text added to your domain’s DNS settings (usually in your hosting provider or domain registrar dashboard). Let's look at this example:

v=DMARC1; p=reject; rua=mailto:reports@yourdomain.com

Now let’s decode all the options you can use:

The 3 DMARC Policy Modes

1. p=none

• Just monitor. Emails are not blocked.
• Use this to start collecting data.
• Best for the first 1–3 weeks.

2. p=quarantine

• Suspicious emails go to the spam folder.
• A good middle ground. You start filtering while keeping risk low.

3. p=reject

• Fully enforced. Email providers block unauthorized emails.
• Your best protection, required for BIMI and full trust.
• Use after verifying your senders are aligned (via reports).

• RUA: Daily aggregate reports (XML files) sent by inbox providers. Shows who is sending email on your behalf, whether it passed or failed SPF/DKIM, and where it came from.
• RUF: Optional forensic reports for individual failures (often not widely supported due to privacy concerns).

1. Start with Monitoring

• Set p=none, add rua=mailto:yourreports@yourdomain.com

• Wait 1–2 weeks, collect reports.

2. Analyze Who’s Sending

• Use the reports to identify all legitimate senders (Mailchimp, Google Workspace, CRM tools, etc.)

• Make sure each sender is set up with proper SPF and DKIM.

3. Fix Alignment Issues

• Ensure DKIM and SPF records match your domain (d= and Return-Path).

• Set adkim=s and aspf=s for strict alignment once you’re confident.

4. Move to Enforcement Gradually

• Start with p=quarantine; pct=25, then raise to 50%, then 100%.

• Finally set p=reject when confident.

5. Maintain and Monitor

• Keep reports active. Even with p=reject, attackers may try new tricks.

• Update your SPF and DKIM records when you add new platforms.

Need assistance? Schedule a meeting with us; we'll help you set everything up. 

v=DMARC1; p=reject; rua=mailto:dmarc-reports@yourdomain.com; ruf=mailto:alerts@yourdomain.com; sp=reject; adkim=s; aspf=s; fo=1

This tells inbox providers:

1. Block all unauthenticated emails (p=reject)

2. Send reports to you daily (rua)

3. Be strict with alignment (adkim=s, aspf=s)

4. Enforce on subdomains too (sp=reject)