Defaults.Exposed

Add a DKIM record in Squarespace

Setting up DKIM on Squarespace comes down to two moves: get the selector and the public key from whoever runs your mailboxes, then publish that key as a DNS record wherever your domain’s DNS is answered. The record comes first on this page because a person who can read one can tell a good paste from a broken one.

Squarespace is a website builder and DNS host for the domain. It publishes the DKIM record once you add it, but it does not send business email and does not generate DKIM keys.

What DKIM proves, and where the key has to live

DKIM (DomainKeys Identified Mail) puts a signature on each message sent from your domain. The mail platform signs with a private key it keeps to itself. The receiving server pulls the selector out of the DKIM-Signature header, looks up <selector>._domainkey.yourdomain.com in DNS, and checks the signature against the public key it finds there. A match tells the receiver two things: the message came from a system holding your private key, and nobody changed the body or the signed headers on the way.

That lookup is why the record goes where your DNS lives. Receivers don’t ask your mail platform for the key, and they don’t ask your registrar unless it happens to run the zone. They ask whichever nameservers your domain delegates to, and only the copy held there counts. The DKIM guide covers the check from the receiver’s side; this page covers the publishing side.

Two parties share the record and neither can do the other’s part. The mail platform generates the key pair inside its own console, keeps the private half, signs outgoing mail with it, and hands you the public half plus a selector. The DNS host publishes what you paste and has no way to invent a value that would verify.

Squarespace publishes the TXT record exactly as entered once the record is saved. It does not generate the key, does not know when the mail provider expects authentication switched on, and does not sign any mail itself.

The record, tag by tag

Most platforms hand you a TXT record. Its value is a short run of tags separated by semicolons, and a typical one begins v=DKIM1; k=rsa; p= followed by the key. v=DKIM1 names the version and, when present, has to come first. k=rsa names the key type; k=ed25519 exists, and a platform that supports it will say so. p= carries the public key itself, hundreds of characters of base64 with no spaces, and it’s the one tag a receiver insists on.

Three optional tags matter. t=y marks the key as testing, so receivers treat a failed signature as if the message carried none. t=s says the identity in the signature has to be your domain itself, with no subdomain in front of it. h=sha256 limits the hash to the algorithm receivers use anyway.

Start with the value as your platform issued it, character for character, and don’t tidy it. Once mail is flowing, tighten in two places. If t=y is present, remove it so a failure counts as a failure. If the platform offers a 2048-bit key alongside a 1024-bit one, pick 2048, since it’s the length platforms now issue by default and receivers accept it.

Rotation stays the platform’s job: when it issues a new key under a new selector, you publish the new record and leave the old one up until nothing signs with it any more.

Some platforms give you a CNAME instead. The name is still <selector>._domainkey, and the target is a host on the platform’s own servers that holds the TXT value, which lets the platform rotate keys without you touching DNS again. If you were given a CNAME, publish a CNAME. Converting the target into a TXT record publishes a hostname where receivers expect a key.

The selector is the half people underrate. A receiver builds its lookup from the s= tag in the header, so the name you publish has to match the one the platform signs with, letter for letter. selector1 and selector2 are different keys, and so are mail and mail1. For DMARC alignment the d= in the signature also has to be your domain or a subdomain of it.

Confirm who answers DNS for your domain

A record saved in a console that your domain doesn’t delegate to is invisible to receivers, whatever that console reports.

A DKIM record only works where the domain’s nameservers point. If the domain was registered with Squarespace, or an outside domain was connected and Squarespace was left to manage its DNS, Squarespace is the right place to add the record. If the nameservers point at another company, add the record there instead. Open the domain in the Squarespace account and check its DNS or nameserver settings to confirm which case applies.

Add the record in Squarespace

Copy both pieces from the platform’s DKIM or email authentication page and keep that tab open until the check at the end passes. Laid out the way Squarespace expects it, the record looks like this:

Type: TXT
Host: google._domainkey
Data: v=DKIM1; k=rsa; p=[public key string from your provider]

Set Type to TXT. In the Host field enter only the selector prefix the mail provider issued, such as google._domainkey or selector1._domainkey, because Squarespace appends the domain name automatically. In the Data field paste the full key value beginning v=DKIM1; k=rsa; p= exactly as the provider supplied it, with no added quote marks. Squarespace does not expose a separate TTL field for this record type.

  1. Sign in to the email provider’s admin console, not Squarespace, and find its email authentication or DKIM section.
  2. Generate a DKIM record for the domain and keep that provider page open while copying the two values it returns.
  3. Sign in to Squarespace and open the Domains area from the account menu.
  4. Click the domain that needs the record, then open its DNS settings, labelled DNS, DNS Settings, Advanced DNS or Custom Records.
  5. Add a new custom DNS record and set the Type field to TXT.
  6. In the Host field, sometimes labelled Name, enter only the selector the provider gave, such as google._domainkey, with no domain name added on the end.
  7. In the Data field, sometimes labelled Value, paste the long key exactly as the provider gave it, then save the record.
  8. Return to the email provider’s console and switch authentication on, if the provider requires that separate step.

Before you save, compare the last few characters of the pasted value with the platform’s page, because a copy that stops early publishes a key that will never verify, and the console won’t warn you. Check the selector in the name against the platform’s page in the same pass.

A few traps are specific to Squarespace:

Save, then wait, then check

DNS changes at Squarespace take a few minutes up to a couple of hours before the record is confirmed and DKIM starts validating. The saved record appears in the same DNS settings screen used to add it, under the domain’s custom records list.

Once the record shows in the console, run the free scan against your domain. It asks DNS for the selector the way a receiving server does and tells you in plain words whether the key is published and readable.

Return to the same DNS settings screen in Squarespace and confirm the TXT record is listed with the correct Host and Data before checking it at the mail provider.

A second check closes the loop. Send a message from the domain to a mailbox you control and open the Authentication-Results header. dkim=pass with your domain in header.d= means the signature verified against the key you published. dkim=fail or dkim=none with the record in place points at the selector or at the platform side, and the next section says where to look.

When the key is missing or malformed

Without a record at the selector, the receiver gets no key and the message carries no verified signature. It won’t bounce on that alone, though DMARC then has only SPF to lean on, and SPF breaks on forwarding, so the quote a customer forwards to a colleague arrives with neither.

A malformed record fails in the same quiet way: a p= value cut short, a stray space or line break in the middle, a doubled host such as mail._domainkey.yourdomain.com.yourdomain.com, or a selector that’s off by one character, and the receiver logs dkim=fail or dkim=permerror and moves on. You hear nothing unless DMARC reports are arriving, and the DMARC piece shows how those reports expose a DKIM failure per sending source.

The census shows how ordinary that silence is. Of the 75,823,110 domains where the September 2026 census could run the DKIM check, it found a key at a known selector on 37,999,462 (50.1%). That check works the way any checker does: there’s no way to list the DKIM records on a domain, so it can only ask for selectors it knows to try, and a platform with an unusual selector can read as absent when the key is fine.

If your scan reports nothing found while the record sits in the console, finding your DKIM selector shows how to read the live selector out of a sent message’s headers before you change anything.

Work a failure in order: the selector spelling first, the nameservers second, then the tail of the pasted value, then whether the platform still needs you to switch signing on.

Figures as of 5 September 2026, from the September 2026 edition of the defaults.exposed census. Census numbers move every month; the current values are on the census data page.