What Happens If DMARC Is Missing?

Why DMARC Matters Now

In February 2024, Google and Yahoo implemented new requirements for email senders. If you send more than 5,000 emails per day to Gmail or Yahoo users, you must have:

• A valid SPF record
• Working DKIM signing
• A DMARC policy (even a basic one)

Even if you send fewer emails, having DMARC significantly improves your email deliverability and protects your domain from being spoofed by spammers.

What Happens Without DMARC

Without a DMARC record, several bad things can happen:

1. Your Emails Go to Spam

Email providers see missing DMARC as a sign that you don't take email security seriously. This makes your emails more likely to be flagged as spam.

2. Emails May Be Rejected Entirely

For bulk senders (5,000+ emails/day), Gmail and Yahoo may reject emails outright if DMARC is missing. Not spam folder - completely rejected.

3. Spammers Can Impersonate You

Without DMARC, there's no policy telling email providers what to do when someone spoofs your domain. Spammers can send phishing emails that look like they're from you.

4. No Visibility Into Problems

DMARC can send you reports about emails sent using your domain. Without it, you have no idea if someone is abusing your domain or if your legitimate emails are failing authentication.

What a DMARC Record Looks Like

A DMARC record is a DNS TXT record at _dmarc.yourdomain.com. Here's an example:

Let's break this down:

• v=DMARC1 - Identifies this as a DMARC record
• p=quarantine - Policy: send failing emails to spam
• rua=mailto:... - Where to send aggregate reports (optional)

DMARC Policies Explained

The p= part of DMARC tells email providers what to do when an email fails SPF and DKIM checks:

The Simplest DMARC Setup

If you just need to meet the Google/Yahoo requirements, here's the simplest DMARC record you can use:

This tells email providers to send suspicious emails to spam instead of the inbox. It's not the strictest policy, but it's a good balance between protection and avoiding false positives.