SPF, DKIM and DMARC for IONOS Mail
Short answer: IONOS Mail mail passes Gmail, Yahoo and Microsoft checks when you turn on DKIM with your own domain, add include:_spf-us.ionos.com to your one SPF record
and publish a DMARC record at _dmarc (start with p=none). The exact records and clicks are below.
| SPF | TXT at @ | v=spf1 include:_spf-us.ionos.com ~allUS accounts (MX mx00.ionos.com) use include:_spf-us.ionos.com; European accounts (MX mx00.ionos.de, .co.uk, .es and so on) use include:_spf-eu.ionos.com. Copy the value your IONOS DNS page shows. Combine with your other senders → |
|---|---|---|
| DKIM | CNAME / TXT | Three CNAME records: s1-ionos._domainkey → s1.dkim.ionos.com, s2-ionos._domainkey → s2.dkim.ionos.com and s42582890._domainkey → s42582890.dkim.ionos.com. |
| DMARC | TXT at _dmarc | v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.comStart with p=none and a
mailbox you read, or a free report address that turns the reports into a dashboard; build your own. |
Step by step
- Domain on IONOS name servers (the default)? IONOS adds MX, SPF and DKIM automatically. Check in Domains & SSL → DNS that they are still there, then do the DMARC step.
- DNS somewhere else? Add MX records at
@formx00.ionos.comandmx01.ionos.com(or your country's hosts, such asmx00.ionos.co.uk), and delete the old MX records. - Add the SPF include for your region (see above) to your one SPF record at
@. - Add the three DKIM CNAME records exactly as listed (CNAME, not TXT).
- Set up DMARC at
_dmarcwithp=noneand your ownruaaddress, then move toquarantineonce the reports are clean. - IONOS says changes can take up to 72 hours worldwide; then check the domain below.
Mistakes that break it
- IONOS often points
_dmarcat its own default (a CNAME todmarc.ionos.com,p=nonewith no reports). To get reports, delete that CNAME first: a name can't hold a CNAME and a TXT record at the same time. - Removed the DKIM records by accident? IONOS warns mail may stop being delivered correctly. Add all three back.
s42582890has no key published at the moment. That is normal: keep all three CNAMEs so IONOS can rotate keys.- Old 1&1 domains may still show
1and1.comhost names; IONOS says they work the same way.
Check that it worked
After the fix, send a test email to see SPF, DKIM and DMARC pass on a real message, then keep an eye on it: free DMARC monitoring shows every service that sends mail as your domain and which ones fail, in plain English.
Get it fixed on Fiverr
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