Connect your domain on IONOS
IONOS labels the same field two different ways — here is which is which.
IONOS adds your domain to whatever you type
Enter names without your domain — _mailflat-verify, not _mailflat-verify.acme.com. Typing the full name stores it as _mailflat-verify.acme.com.acme.com, and no amount of waiting will make that verify. In the dashboard, keep the Provider dropdown on name only and use the copy button next to each Host.
Where the DNS editor is
- Log in to IONOS
- Domains & SSL → your domain
- DNS tab
- Add record
Field names here: Host name (Name for MX) for the record name, Value (Points to for MX) for the value, Priority for MX priority.
The five records, as IONOS wants them
Your real values are on Domains in the dashboard — the verification token and the DKIM key are unique to your domain. Everything else looks exactly like this.
| Type | Host name (Name for MX) | Value (Points to for MX) | What it does |
|---|---|---|---|
| TXT | _mailflat-verify | mf-verify-… (yours is in the dashboard) | Proves you own the domain. Verification fails without it. |
| MX | @ | mail.mailflat.net.Priority 10 — Priority | Routes incoming mail to MailFlat. |
| TXT | @ | v=spf1 include:mailflat.net ~all | Authorises MailFlat to send for your domain. |
| TXT | mail._domainkey | v=DKIM1; k=rsa; p=… (yours is in the dashboard) | Signs your outgoing mail. |
| TXT | _dmarc | v=DMARC1; p=none; | Tells receivers what to do when a check fails. |
IONOS specifics
IONOS adds your domain for you. Use @ for the root, short names elsewhere.
The field is called *Host name* for TXT records and *Name* for MX — same thing.
The default TTL of one hour is fine.
Then verify
Back on Domains, press Verify. If it fails, the message says what is actually wrong — including the case where your records landed one level too deep, with the exact name we found them under. DNS changes are usually visible within minutes; a failure that names a wrong record will not fix itself by waiting.
More on custom domains: Custom domains (BYOD).