Short answer: SPF, DKIM, and DMARC are three records you add to your sending domain so inbox providers trust that your email is really from you. SPF lists who is allowed to send for your domain, DKIM signs your messages so they cannot be tampered with, and DMARC tells inboxes what to do if a message fails those checks. Set up all three before you send cold email, or many messages will never reach the inbox.
What each record does
| Record | Job |
|---|---|
| SPF | Says which servers may send for your domain |
| DKIM | Adds a signature proving the message is unchanged |
| DMARC | Tells inboxes how to handle messages that fail |
How to set them up
- Find the DNS settings for your sending domain.
- Add the SPF record your email provider gives you.
- Enable DKIM in your provider and add its record.
- Add a DMARC record, starting in a monitoring mode.
Check it is working
After adding the records, send a test email to an account you control and view the message details or headers to confirm the checks pass. Many free tools can also check your domain and show whether each record is set up correctly.
Common mistakes
- Adding more than one SPF record, which breaks it.
- Forgetting to enable DKIM in the provider before adding the record.
- Setting a strict DMARC policy before confirming everything passes.
Frequently asked questions
Q: Do I really need all three?
A: Yes. Modern inboxes expect SPF, DKIM, and DMARC, and messages without them are far more likely to be filtered.
Q: Where do I add these records?
A: In the DNS settings for your domain, usually through your domain registrar or hosting provider.
Q: How long until they work?
A: DNS changes can take from minutes to a day to spread, though often it is quick.
Q: What DMARC policy should I start with?
A: Start in a monitoring mode so you can confirm everything passes before enforcing anything stricter.
Q: Is this a one time setup?
A: Mostly yes, but review it if you change email providers or add new sending tools.
Next step
Pair this with a separate sending domain and inbox warmup. For a full path, see the courses or the free live session.
