The Basics of Form Emails: What Are SPF, DKIM, and DMARC?
If you’ve ever sent out a form on your website and felt the frustration of not receiving the emails in your inbox, you’re not alone. It can feel like sending a letter into a black hole.
The reason behind this issue often boils down to a few key email security and authentication settings: SPF, DKIM, and DMARC.
Let’s break these down in a way even a kindergartener (or a busy professional) can understand.
Imagine you’re sending a letter to your friend. You put it in an envelope, write your name and return address on it, and drop it in the mailbox. Before it gets delivered, the mailman checks a few things.
SPF (Sender Policy Framework)
SPF is like a list of approved senders. It tells the mailman, “Hey, this letter really came from Jessica’s house, so it’s okay to deliver it.”
If the mailman doesn’t see Jessica’s address on the list, he might not deliver the letter.
DKIM (DomainKeys Identified Mail)
DKIM adds a special stamp to your letter. This stamp proves that nobody opened or changed your message while it was on its way.
It’s like sealing the envelope with a unique wax seal that only Jessica’s house uses.
DMARC (Domain-based Message Authentication, Reporting, and Conformance)
DMARC is the bossy rulebook. It tells the mailman what to do if:
- The address isn’t on the approved list (SPF fails), or
- The seal is missing or broken (DKIM fails)
Should he deliver it anyway, mark it as suspicious, or throw it away?
Together, these three tools help email providers trust your messages so they don’t get lost, blocked, or sent to spam.
Why Does This Matter for Form Emails?
When someone fills out a form on your website, that information often gets sent to you via email.
But here’s the catch: the email isn’t always sent directly from your website’s domain. It might be sent from a server or third-party tool your site uses (like Mailchimp, Google Forms, or a custom form plugin).
If SPF, DKIM, and DMARC aren’t set up correctly, email servers may not trust those messages and could:
- Mark them as spam (and you’ll never see them)
- Reject them outright (goodbye, email)
How to Fix This Problem
To improve deliverability, you’ll want to set up SPF, DKIM, and DMARC records correctly in your domain’s DNS settings.
1) SPF Record
Think of SPF as your guest list for a party. Only the people on the list are allowed in.
- Add an SPF record to your domain’s DNS.
- This record tells email servers which mail servers (your web server or third-party service) are allowed to send email on behalf of your domain.
2) DKIM Record
DKIM adds that unique “wax seal” to your emails, proving the message hasn’t been changed in transit.
- Set up a DKIM record in DNS using a public key.
- The private key stays on the mail server or service sending your emails.
- This helps recipients verify the email is authentic and untampered.
3) DMARC Record
DMARC tells email servers what to do if SPF or DKIM checks fail.
- Create a DMARC record in DNS that sets your policy.
- You can instruct servers to monitor, quarantine (send to spam), or reject suspicious messages.
- DMARC can also send you reports so you can see what’s failing and why.
What If You’re Not Tech-Savvy?
If all this sounds like a foreign language, don’t worry. You have options.
- Work with your web host: Many hosting providers can help you add DNS records for SPF, DKIM, and DMARC.
- Use third-party instructions: Services like Google Workspace, Microsoft 365, or Mailgun provide step-by-step setup guides.
- Hire an expert: Sometimes it’s worth bringing in a pro. Consider it an investment in making sure your leads and inquiries don’t disappear.
Final Thoughts
Think of SPF, DKIM, and DMARC as the bouncers, security cameras, and managers of your email club. They help ensure only legitimate emails get through — and that your important form messages don’t vanish into spam or rejection folders.
If you’re not receiving your form emails, take a closer look at these settings. With the right configuration, you can ensure your messages land safely in your inbox — every time.