Add a DMARC record in IONOS

Updated 2026-09-30 · Setup Guides

If your domain's nameservers look like ns1045.ui-dns.com, ns1045.ui-dns.de, ns1045.ui-dns.org and ns1045.ui-dns.biz — the number varies — its DNS is at IONOS: that's the pattern IONOS documents for its default nameservers. You publish the record in the domain's DNS settings.

The record you're publishing

The Value is your DMARC policy. If you're setting up monitoring with DMARCmetric, Add your first domain generates the full value for you, including your workspace's unique rua= reporting address — copy it from the wizard with the copy button rather than retyping it. p=none is the right starting policy: it monitors everything and blocks nothing.

IONOS's DNS help says a domain has no TXT records by default — but look for an existing _dmarc record anyway before adding one.

The steps below add a new record, for a domain with no DMARC record yet. If _dmarc already has one, don't add another — edit the one you have instead.

Step by step

1. Log in to IONOS and go to Domains & SSL.
2. For your domain, click the gear symbol under Actions and select DNS.
3. Your existing records are listed there. If one is a TXT record with the host name _dmarc, edit it instead.
4. Click Add Record and, under Type, select TXT.
5. In Host name, enter _dmarc. IONOS creates _dmarc.your-domain.com from it automatically.
6. In Value, paste your v=DMARC1; … value.
7. Optionally select a TTL, then click Save.

IONOS says changes take effect at IONOS immediately, and it may take up to an hour until they're effective everywhere.

If you already have a DMARC record

A domain can have only one DMARC record, so don't click Add Record — change the one that's there. Never add a second _dmarc record next to the old one: with two, email providers ignore both.

1. In the DNS section, find the existing TXT record whose host name is _dmarc, click the gear symbol under Actions and select Edit record.
2. Edit that record.
3. What you change depends on what DMARCmetric shows you — check which of these two it is before you touch anything:
   • If DMARCmetric shows only an address (mailto:rua+…, shown when it couldn't read your DNS at that moment), don't replace anything. Add that address to your existing rua= tag, separated by a comma. If the record has no rua= tag, add one: rua= followed by the address, separated from the tag before it by a semicolon. Leave your policy and every other tag as they are.
   • If DMARCmetric shows a full record (starting with v=DMARC1), replace the record's whole Value with it. That value is built from your existing record: your policy and tags are kept, and it includes your DMARCmetric reporting address.
4. Save the record.

If there are several. If the list shows more than one TXT record at _dmarc that starts with v=DMARC1, delete the extras and keep one, then change the one you keep exactly as in step 3: if DMARCmetric shows a full record, that record becomes its Value; if it shows only an address, add the address to its rua= tag. Until only one is left, receivers treat the domain as having no DMARC policy at all.

Verify it's live

From a terminal:

dig TXT _dmarc.example.com +short

You should see your v=DMARC1; … value echoed back in quotes. No terminal handy? Run your domain through the free DMARC checker — it fetches the live record and validates the syntax, which dig won't do. And if you added the record as part of DMARCmetric onboarding, press Verify DNS in the wizard; Verify your domain explains each result it can give you.

Common mistakes

• Adding your domain to the host name. IONOS adds .your-domain.com itself — enter only _dmarc.
• Two _dmarc records. A domain may have only one DMARC record; receivers treat two TXT records at _dmarc as no valid policy at all. If a record already exists, edit it — don't add a second.
• Editing the value by hand. A missing semicolon between tags, mailto; instead of mailto:, or a mangled reporting address all invalidate the record or send your reports nowhere. Copy-paste the whole value, then confirm with the checker.

If some of your domains live at other providers, the same record works everywhere — the Cloudflare and GoDaddy walkthroughs cover those panels.