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What DNS records does a business email domain need?

By Samuel ChenardJuly 30, 20268 min read
What DNS records does a business email domain need?

Every business email domain needs four DNS records to send and receive mail that lands in the inbox: an MX record so other servers know where to deliver your mail, and three authentication records — SPF, DKIM, and DMARC — that prove your mail is genuinely from you. MX makes email work at all; the authentication trio is what Gmail, Yahoo, and Microsoft now require before they trust bulk mail from your domain. Everything else is optional hardening.

At a glance

Quick Takeaways

  • An MX record points to the mail servers that accept incoming email for your domain — without it, you cannot receive mail.
  • An SPF record (a TXT record) lists which servers are allowed to send mail using your domain.
  • A DKIM record (a TXT or CNAME record) publishes the public key that verifies your mail's cryptographic signature.
  • A DMARC record (a TXT record at _dmarc.yourdomain.com) tells receivers what to do when SPF or DKIM fails and where to send reports.
  • Gmail and Yahoo require SPF, DKIM, and DMARC for anyone sending bulk mail as of February 2024; Microsoft began enforcing the same in May 2025.
  • Optional records — MTA-STS, TLS-RPT, BIMI, and PTR — add encryption guarantees, reporting, and brand signals on top of the core four.

What is the difference between records that carry mail and records that authenticate it?

DNS records for email fall into two jobs. The first job is routing: telling the internet where your mail lives. The second is authentication: proving that a message claiming to be from your domain really is.

Only one record does the routing job — the MX record. The rest are authentication and policy records that receiving servers read to decide whether to trust, quarantine, or reject a message. A domain can have a perfectly valid MX record and still have every message marked as spam, because routing and trust are separate questions. This is why "email works" and "email lands in the inbox" are not the same milestone.

What does the MX record do?

The MX (Mail Exchange) record tells other mail servers which hosts accept incoming email for your domain, and in what priority order. When someone emails you@yourdomain.com, their server looks up your domain's MX record and delivers to the host with the lowest priority number first.

If you use Google Workspace, Microsoft 365, or a hosted provider, they give you the exact MX values to publish. A typical setup points to one or two provider hostnames:

  • 1 aspmx.l.google.com (Google Workspace, lowest number = highest priority)
  • Or 0 yourdomain-com.mail.protection.outlook.com (Microsoft 365)
Get this wrong and inbound mail bounces with a no MX record found error. You can confirm what is published with an MX record lookup. For the full mechanics, see what an MX record is.

What does the SPF record do?

SPF (Sender Policy Framework) is a TXT record that lists the servers authorized to send mail using your domain in the envelope. A receiving server checks the sending IP against this list; if the IP is not authorized, SPF fails.

An SPF record is a single TXT record on the root domain that starts with v=spf1 and ends with an all mechanism:

Technical exampletext
v=spf1 include:_spf.google.com ~all

The include pulls in your provider's authorized senders, and ~all (soft fail) or -all (hard fail) sets what happens to everything else. You may only publish one SPF record per domain — a second one breaks both. SPF also has a hard limit of 10 DNS lookups, which is the most common way it quietly fails. See SPF record syntax explained for the mechanisms and qualifiers, and test yours with the SPF checker.

What does the DKIM record do?

DKIM (DomainKeys Identified Mail) adds a cryptographic signature to every message header. The matching public key is published in DNS so receivers can verify the signature was created by you and that the message was not altered in transit.

DKIM lives at a selector subdomain — for example selector1._domainkey.yourdomain.com — as either a TXT record holding the key or a CNAME that points to a key your provider hosts. Your email platform generates the key pair and tells you exactly what to publish; you rarely type the key by hand. Because the selector is provider-specific, a domain can carry several DKIM records at once (one per sending service). Read what DKIM is for the signing flow, and verify a selector with the DKIM checker.

What does the DMARC record do?

DMARC (Domain-based Message Authentication, Reporting, and Conformance) ties SPF and DKIM together and tells receivers what to do when a message fails both. It is a TXT record published at _dmarc.yourdomain.com:

Technical exampletext
v=DMARC1; p=none; rua=mailto:reports@yourdomain.com

The p tag is the policy: none (monitor only), quarantine (send failures to spam), or reject (block them). The rua tag is where aggregate reports are sent, which is how you discover who is sending as your domain before you tighten the policy. Best practice is to start at p=none, read the reports, fix your legitimate senders, then move to quarantine and finally reject. See what DMARC is for the full tag reference, and generate a record with the DMARC checker.

Which optional DNS records are worth adding?

Once the core four are in place, these records add real security and visibility for domains that need it:

  • PTR (reverse DNS): maps your sending IP back to a hostname. Providers expect a matching forward and reverse record on any server you send from — missing PTR is a common spam trigger. See what a PTR record is.
  • MTA-STS: forces inbound mail to arrive over encrypted TLS and refuses to downgrade, closing a man-in-the-middle gap SMTP leaves open. See what MTA-STS is.
  • TLS-RPT: a TXT record that asks receivers to report failed TLS connections, so you learn when encrypted delivery breaks. Providers like Google document how to read these reports.
  • BIMI: publishes your verified logo so supporting inboxes show it next to authenticated mail — but it requires DMARC at enforcement first. See what BIMI is.
  • AAAA: the IPv6 equivalent of an A record, needed if your mail host is reachable over IPv6. See what an AAAA record is.

Common issues with business email DNS records

Why is my mail still going to spam after I added SPF, DKIM, and DMARC?

Publishing the records is not the same as passing them. A record with a typo, an SPF record over the 10-lookup limit, or a DKIM selector that does not match what your platform signs with will all authenticate as fail even though the record exists. Run each one through a checker rather than trusting that "the record is there."

Why do I have two SPF records and which one wins?

Neither. A domain may publish only one v=spf1 TXT record. A second one makes SPF return a permerror, which most receivers treat as a fail. Merge every sender into a single record using include mechanisms and delete the duplicate.

My MX record is correct but mail bounces — what else could it be?

Check that the MX hostname itself resolves to an A or AAAA record, and that no leftover MX entry points at a decommissioned server. A high-priority record aimed at a dead host will be tried first and stall delivery before the working record is reached.

DKIM verified yesterday and fails today

Your provider rotated the key, or you republished the record and trimmed a character. DKIM keys are long; DNS interfaces sometimes truncate or wrap them. Re-copy the exact value your platform shows and confirm the selector name matches.

Questions readers ask

Frequently asked questions

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Samuel Chenard

Written by

Samuel Chenard

CEO & Co-Founder, Palisade

Samuel Chenard is the CEO and co-founder of Palisade, AI-first DMARC software for IT teams and MSPs, from one domain to thousands.

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