What is a DKIM selector?

A selector is a short label you choose (e.g. "mail", "s1", "google") that namespaces the DKIM public key in DNS. It forms part of the hostname: ._domainkey. . Using multiple selectors lets you rotate keys without disrupting mail flow.

Where do I get my DKIM public key?

Your email provider or mail server software generates the public/private key pair. The private key stays on your mail server; the public key is what you publish in DNS. Most providers show you the public key in their admin panel or DKIM setup guide.

Should I include the PEM header lines in the DNS record?

No. DNS TXT records must contain only the raw Base64-encoded key data without the "-----BEGIN PUBLIC KEY-----" header and footer lines. This tool strips them automatically when you paste PEM format.

What DNS record type and hostname should I use?

Always use a TXT record. The hostname is " ._domainkey. " — for example, if your selector is "mail" and your domain is "example.com", the hostname is "mail._domainkey.example.com".

What is the p= tag in the DKIM record?

The p= tag holds the Base64-encoded public key. If p= is empty, it means the key has been revoked and DKIM verification will fail for that selector. Always ensure p= contains the full key value.

How long does DNS propagation take after publishing the record?

DNS changes typically propagate within minutes to a few hours, but can take up to 48 hours in rare cases. You can verify the record is live using the dig or nslookup commands, or an online DNS lookup tool.

DKIM Record Generator

Name: DKIM Record Generator
Availability: InStock
Author: Nham Vu

Paste your public key and selector to instantly generate the correct DKIM DNS TXT record for your domain.

DKIM Record Builder

Selector (e.g. mail, google, s1)

Domain (optional — used for hostname preview)

Key Type

RSA Ed25519

Allowed Hash Algorithms (h= tag)

sha256 sha1

Service Type (s= tag — * means any service)

Public Key (Base64 or PEM — header lines are stripped automatically)

Fill in the form and click Generate to build your DKIM record.

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