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Set up DMARC for example.com

Publish one DMARC TXT record, monitor aligned SPF and DKIM results, then move safely from reporting to quarantine or reject.

DMARC
Recommended methodEmail DNS and seal setup
DMARC policy setup

Publish, monitor and enforce safely

  1. 1

    Inventory every legitimate sender

    List every service that sends with your domain in the visible From address, including hosted mail, website forms, invoices, marketing, support desks, gateways and reseller platforms. A forgotten sender can fail after enforcement begins.

  2. 2

    Complete SPF and DKIM first

    Send external test messages from every service. DMARC passes when at least one authenticated SPF or DKIM domain aligns with the visible From domain. Correct missing or unaligned authentication before enforcing a DMARC policy.

  3. 3

    Create a reporting mailbox

    Create the aggregate-report mailbox shown in the record, use a monitored group or choose a trusted DMARC reporting service. Reports help identify legitimate and unauthorized sending sources.

  4. 4

    Publish the monitoring record

    At the authoritative DNS provider create one TXT record at _dmarc for the sender domain. Start with p=none so reports can be reviewed without asking receivers to quarantine or reject failing mail.

  5. 5

    Test the published record

    Wait for DNS propagation, confirm exactly one DMARC record is returned, then send new messages from every legitimate system. Check Authentication-Results and the aggregate reports for aligned SPF, DKIM and DMARC results.

  6. 6

    Fix failures before enforcement

    Correct every legitimate source that fails alignment. Remove obsolete services and investigate unknown sources. Keep the monitoring policy until normal mail streams consistently pass.

  7. 7

    Increase the policy in stages

    Replace the monitoring record with p=quarantine only after reviewing reports. Move to p=reject only when legitimate mail continues to pass. Publish one policy record at a time; do not add all three examples.

  8. 8

    Recheck VerifySeal

    Run the email DNS check from the customer order or seal. Keep monitoring reports and repeat the check after changing senders, DNS providers or mail services.

Open current IETF DMARC standard (RFC 9989) ↗
DMARC alignment

SPF or DKIM must authenticate and align

The sender domain must continue to publish a valid SPF record, the selected DKIM key and a DMARC policy. VerifySeal automatically rechecks these records according to the administrator schedule. For High Security messages, DKIM must cover the final Message-ID, VEM header and completed body.

  • SPF authorizes sending services
  • DKIM verifies the signed message domain
  • DMARC publishes the domain policy
Testing checklist

Confirm the installation is working

01

One record

DNS returns exactly one TXT policy at _dmarc.example.com.

02

Aligned mail

External test messages from every legitimate service report a DMARC pass aligned with the visible From domain.

03

Reports arrive

The reporting mailbox receives aggregate data and unknown or failing sources are investigated.

04

Staged policy

Quarantine or reject is used only after legitimate mail consistently passes during monitoring.

Platform notes
  • Publish exactly one DMARC TXT record for a domain. Multiple DMARC records can make the policy invalid.
  • Replace the example reporting address with a real monitored mailbox. If reports are not wanted, omit rua instead of publishing an address that does not exist.
  • Relaxed alignment (adkim=r and aspf=r) is the safer starting point for most organizations. Change to strict alignment only after testing every legitimate sender.
  • A rua address on another domain can require an additional authorization DNS record at that destination.
  • The current DMARC standard removed the old pct tag. Stage rollout by reviewing reports and deliberately changing p=none to p=quarantine and then p=reject.