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DNS Change Impact Checklist

Check risks before changing NS, MX or TXT records.

Changing DNS records is sensitive — it can affect site access, mail delivery and certificates all at once. A wrong NS or MX change can lose mail or take the site down for hours. This checklist walks through what to verify beforehand, grouped by area, and scores your readiness.

Run it before any DNS change: server migration, mail host change, nameserver swap, or adding a CDN.

Why lower TTL first?

TTL is how long resolvers cache a record. With a high default, stale data lingers after a change. Lowering it to 300s a day or two ahead speeds propagation and rollback. Raise it back once things are stable.

A safe cutover order

Fully set up the new server/mail and confirm direct access and send/receive.
Lower the TTL of the records you'll change.
Cut over during a low-traffic window.
Immediately test site, mail and certificate.
Once stable, restore the original TTL.

Frequently asked questions

How long does DNS propagation take?

It depends on the record's prior TTL. If you didn't lower it ahead of time, stale data can persist up to the old TTL (often 1–24h).

What order for moving mail and web together?

Fully set up the new server and mail, verify direct access and send/receive, then switch A/MX — ideally in stages.

Why check CAA records?

CAA limits which certificate authorities may issue for your domain. If you switch CA but CAA blocks it, issuance fails.

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