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Set up DKIM on IONOS

DKIM (short for DomainKeys Identified Mail) is a small, invisible stamp added to every email you send. It proves the email really came from your domain and wasn't faked along the way. If you haven't already, read our main DKIM guide first — it explains what DKIM is and why it matters, in plain English. This page just covers the exact clicks for IONOS, one of the most common places people manage their domain.

Step 1: Get your DKIM record from your email provider

Before you touch IONOS, you need two things from your email provider (Google Workspace, Microsoft 365, Mailgun, SendGrid, Zoho, or whichever one sends your mail):

  1. A selector — a short label, like google or s1.
  2. A value — a long string of letters and numbers.

Your email provider's admin dashboard will show you these under a setting called DKIM, DomainKeys, or Email Authentication. Copy both — you'll paste them into IONOS in Step 3.

Step 2: Log in and find your domain's DNS settings

  1. Go to my.ionos.com and log in with your IONOS account.
  2. Find the domain you want to update in your list of domains.
  3. Click the gear icon (⚙) next to that domain, under Actions.
  4. Select DNS from the menu that appears.

Note: IONOS has changed its panel layout over the years. If you don't see a gear icon, look for Domains & SSL in the main menu, click your domain, then look for a DNS or DNS settings tab. Some older IONOS accounts still call this the "Domain Center" — the DNS section works the same way either way.

Step 3: Add a new TXT record

A TXT record is just a plain-text entry in your domain's DNS — think of DNS as your domain's address book, and a TXT record as one more line written into it.

  1. On the DNS settings page, click Add Record.
  2. From the Type dropdown, choose TXT.
  3. In the Host name field, enter your DKIM selector followed by ._domainkey. For example, if your selector is google, enter google._domainkey. (Your email provider's instructions will usually spell out this full host name for you — if they do, just copy theirs exactly.)
  4. In the Value field, paste the long DKIM value your email provider gave you.
  5. Leave TTL on its default setting unless your provider told you to change it.
  6. Click Save.

That's it — your TXT record is now saved in IONOS.

| Field | What to enter | | --- | --- | | Type | TXT | | Host name | Your selector + ._domainkey (e.g. google._domainkey) | | Value | The long DKIM value from your email provider | | TTL | Default is fine |

Double-check for typos before saving. A single missing character in the value field will make DKIM fail even though the record looks like it saved correctly. If you're copying and pasting, make sure no extra spaces or line breaks got added at the start or end.

Step 4: Tell Warmerly your selector

IONOS is a common host for domains where the email provider uses a custom DKIM selector — one that Warmerly doesn't automatically check for. This is exactly why Warmerly has a manual selector field: so you can tell us the exact selector your provider used, instead of waiting on us to guess it.

To add it:

  1. In Warmerly, go to Accounts.
  2. Click into the mailbox you just set up DKIM for.
  3. Go to Settings.
  4. Find the DKIM selector field and type in your selector (just the short label, like google — not the full ._domainkey.yourdomain.com part).
  5. Save.

Warmerly will now check specifically for the record you added, instead of only the common defaults.

Step 5: Wait for it to go live

DNS changes can take up to 24–48 hours to fully take effect, even though IONOS usually applies the change on its end right away. This delay isn't a bug — it's just how the internet spreads DNS updates around the world. If Warmerly still shows "DKIM not found" a few minutes after you save the record, that's normal. Check back later, and it should update on its own once the change has spread.

If it's still showing as missing after two full days, double-check the host name and value in IONOS for typos, and confirm the selector you entered in Warmerly matches exactly.