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Email5 min read· Updated

Set up email DNS while preserving working mail

List every service that receives or sends mail for your domain before changing DNS. Copy the working records and make one reviewed change at a time.

Check the published email records togetherRun the email DNS report, adding your sending service’s DKIM selector when available.
Check email DNS
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    1. Separate receiving from sending

    MX records identify receiving servers. SPF and DKIM help authenticate sending; DMARC relates an authenticated identity to the visible From domain. A website contact form, billing system and newsletter service may each need their own sending configuration. Avoid replacing working MX records with a sender's unrelated instructions.

    2. Publish one SPF policy

    Compare your sending providers' instructions with SPF Checker. Merge authorized senders into one policy rather than publishing competing v=spf1 records. DNS-lookup mechanisms, including nested terms, are limited to at most ten. Preserve the previous record before replacing it.

    3. Use each provider's DKIM selector

    Publish the exact CNAME or TXT record the sending service supplies. Find the selector in its control panel or the s= value of a real message's DKIM-Signature, then use DKIM Checker. A key in DNS does not prove that a message was signed or verified.

    4. Monitor before tightening policy

    Use DMARC Generator with p=none and a report destination you can review. Confirm legitimate SPF/DKIM identities align with From. RFC 9989 removed percentage rollout with pct; its t=y testing signal has compatibility limits with older receivers. Do not rely on it to protect a newly configured sender from rejection.

    Confirm actual messages

    Run Email DNS checks, then send new test messages through each real service to accounts you control. Inspect received headers using Email Header Analyzer. Publication, authentication, acceptance and inbox placement are different outcomes.

    Sources

    Reviewed by NosHost on 26 October 2026. Gmail sender requirements · SPF · DMARC.

    Use the linked tools to confirm each change, then repeat the original test. Review server or DNS changes before applying them to a live site.

    Spotted something out of date? Email [email protected].

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