How to Add a DMARC Record on IONOS
Introduction
DMARC is a TXT DNS record at _dmarc that works with SPF and DKIM so major inbox providers trust mail from your domain. When you authenticate for
systeme.io
email, you receive three CNAME records + one TXT (DMARC). Help article 3964 explains adding that TXT in the IONOS DNS zone with policy p=none.
This guide is DMARC-only. For all CNAMEs plus TXT, see authenticate your domain on IONOS (3965).
Prerequisites
- Domain with DNS managed in IONOS (dashboard access).
- Domain authentication started in systeme.io Settings → Emails (DMARC value in popup / eye icon).
- IONOS login.
Typical systeme.io DMARC Value
v=DMARC1; p=none; rua=mailto:youraddress@yourdomain.com
- p=none — monitoring mode ( How to Create a DMARC Record, 2241).
- rua=mailto:… — aggregate reports; replace placeholder with a real mailbox you control.
IONOS creates _dmarc.yourdomain.com when you enter Hostname _dmarc.
Step-by-Step on IONOS (Article 3964)
- Log in to your IONOS account.
- Open your domain → DNS settings (DNS zone).
- Click Add a record.
- Type: TXT.
- Hostname:
_dmarc(value shown under Name in the systeme.io popup). - Value (or “Points to”): paste the full DMARC string from systeme.io; customize
rua=mailto:. - TTL: default unless you need a specific value.
- Click Save.
Example (illustrative):
- Hostname:
_dmarc - Value:
v=DMARC1; p=none; rua=mailto:hello@yourdomain.com
Verify DMARC and Domain Status
- Wait for DNS propagation (minutes to 48 hours).
- Run a DMARC lookup on your domain.
- In systeme.io Settings → Emails, confirm Verified when all three CNAMEs + TXT are correct.
-
Confirm your sender email address
and check
email headers
for
dmarc=pass.
IONOS-Specific Notes
- Single _dmarc: Remove or edit an existing DMARC TXT before adding a second row.
- IONOS mail vs systeme.io: IONOS-hosted mail may already use SPF/MX records—add systeme.io auth records without breaking required mail DNS unless you understand the impact.
- Funnel CNAME: Connecting the domain for funnels uses different CNAMEs ( connect IONOS domain, 3962)—separate from email authentication.
- Trailing dots: For CNAME “Points to” targets in 3965, follow systeme.io copy exactly (often ends with a dot).
Troubleshooting
| Issue | Fix |
|---|---|
| DMARC lookup empty | Confirm Hostname _dmarc; DNS zone is for the correct domain. |
| Duplicate DMARC | One TXT at _dmarc only. |
| systeme.io Pending | Complete three CNAMEs (3965) + this TXT. |
| Value rejected | Single line, semicolons as in systeme.io copy; no extra quotes. |
| No rua reports | Verify mailbox in rua=mailto exists. |
Frequently Asked Questions
Where in IONOS?
DNS zone → Add a record → TXT (3964).
Hostname?
_dmarc per systeme.io popup.
p=none?
Monitor before quarantine/reject.
With CNAMEs?
Yes—fourth auth record.
Two _dmarc rows?
No—one TXT only.
Last updated: July 3, 2026