Email spoofing is a major problem. Scammers fake sender addresses to phish users, spread malware, or hijack your brand’s reputation.
To crack down on this, Google and Yahoo are enforcing stricter DMARC (Domain-based Message Authentication, Reporting, and Conformance) rules. Anyone sending over 5,000 emails a day must have proper authentication in place – or risk getting blocked.
If you’re a high-volume sender, it’s no longer optional. You need to get DMARC right, or your emails might not make it to the inbox.
What is DMARC?
DMARC is an email security protocol that helps stop spoofing and phishing. It builds on two existing technologies, SPF and DKIM, to verify that messages are actually from the domain they claim to be, and that they haven’t been tampered with.
Here’s how the pieces fit together:
- SPF (Sender Policy Framework): Verifies that the email was sent from an IP address authorized by the domain’s DNS records.
- DKIM (DomainKeys Identified Mail): Uses cryptographic signatures to confirm that the email content hasn’t been modified in transit.
- DMARC: Ties SPF and DKIM together. It lets domain owners publish a policy that tells receiving servers what to do when an email fails those checks: ignore it, quarantine it, or reject it.
A DMARC record includes:
- Policy (p): Tells email providers what to do with messages that fail SPF or DKIM. Options: “none”, “quarantine”, or “reject”.
- Aggregate Reports (rua): A list of email addresses where daily summaries of authentication results are sent. These reports help you monitor who’s sending on your domain’s behalf.
- Forensic Reports (ruf): Optional. Sends more detailed, per-message failure reports for deeper troubleshooting.
What makes DMARC so vital?
DMARC solves real problems. It gives domain owners a way to protect their brand, improve deliverability, and block malicious emails before they reach the inbox. Here’s what makes it worth your time:
- Improved Deliverability: When you publish a DMARC policy, you’re proving that your emails are authenticated and legitimate. Mail providers see this as a trust signal. The result: fewer emails flagged as spam and better inbox placement.
- Better Security Control: DMARC lets you tell receiving servers what to do with unauthenticated emails. That means fewer phishing emails pretending to be from your domain. If someone tries to spoof you, your policy can have their messages quarantined or rejected outright.
- Visibility Into Your Domain: DMARC reports show you who’s sending email using your domain, both legit senders and potential abusers. These insights help you fix misconfigurations and spot suspicious activity fast.
For recipients, DMARC reduces the chance of phishing emails making it through. Fewer fake messages in the inbox means better security for everyone. And when senders get their authentication right, it builds trust – especially for businesses that rely on email to connect with customers.
Google and Yahoo’s DMARC Mandate
As of 2024, Google and Yahoo now require bulk senders, those sending over 5,000 emails per day, to have a valid DMARC policy in place. If you’re hitting that volume and sending to Gmail or Yahoo Mail users, this is no longer optional.
The mandate means you must publish a DMARC record in your DNS. Without it, your emails may get flagged, throttled, or outright rejected. In short: no DMARC, no inbox.
This move is part of a broader push to reduce spam, phishing, and spoofed messages across the ecosystem. It forces senders to take authentication seriously and rewards those who do with better deliverability and sender reputation.
If your business relies on email, this isn’t just a compliance box to check. It’s about staying visible in inboxes and avoiding getting filtered out with the junk.
Steps to Meet the DMARC Requirement
Here’s what you need to do to stay compliant with Google and Yahoo’s DMARC requirements:
1. Check Your Current Setup
Start by auditing your domain. Use a tool like DMARC Checker to see if you already have SPF, DKIM, and DMARC configured – and if they’re working as expected.
2. Choose the Right DMARC Policy
Pick a policy that matches your current readiness:
- p=none: Monitoring only. You’ll get reports but no filtering.
- p=quarantine: Suspicious emails go to spam.
- p=reject: Block unauthenticated emails outright.
If you’re just getting started, begin with “none”, review reports, then move to stricter enforcement as you lock things down.
3. Publish a DMARC Record
Once you’ve chosen a policy, publish your DMARC record as a TXT record in your DNS. It should be added under the _dmarc subdomain of your domain.
A basic record might look like this:
- Name: _dmarc.yourdomain.com
- Type: TXT
- Value: v=DMARC1; p=none; rua=mailto:dmarc-reports@yourdomain.com
Replace yourdomain.com with your actual domain, and set the “rua” address to wherever you want aggregate reports sent.
4. Monitor and Adjust
Check DMARC reports regularly. Look for signs of spoofing or misconfigured senders. Tweak your SPF and DKIM settings as needed to ensure all legitimate mail is authenticated.
Following these steps will help keep your emails out of the spam folder and out of trouble with Google and Yahoo.
Conclusion
The 5,000-emails-a-day threshold from Google and Yahoo is just the starting line. Even if you send fewer messages, your domain can still be spoofed. DMARC gives you visibility and control, regardless of your sending volume. This is not just about compliance – it is about being proactive.
The push for DMARC by major providers highlights the growing importance of email authentication. It is not only about getting into the inbox. It is about protecting your brand, your users, and your credibility. If your business relies on email, now is the time to act.
To recap:
- Audit your current SPF, DKIM, and DMARC setup
- Start with a policy of “p=none” to monitor traffic and gather data
- Move to “quarantine” or “reject” once legitimate sources are covered
- Monitor DMARC reports to identify unauthorized senders and fix misconfigurations
- Make sure all third-party services sending on your behalf are properly authenticated
DMARC is also part of a broader shift in email security. Standards like BIMI and MTA-STS are gaining adoption, and DMARC compliance positions you well for what comes next.
DMARC makes your emails more trustworthy, your domain more secure, and your communication more reliable. It is worth doing, and worth doing now.