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Domains & Authentication

IONOS

Publish the SPF, DKIM, and DMARC records MailBlastr generates for your domain using the IONOS DNS manager.

This guide walks through adding the DNS records MailBlastr generates for a domain using IONOS. Add your domain in MailBlastr first to generate the records — see Managing domains — and keep the DNS records reference open for your exact DKIM record and region.

It is best practice to use a subdomain (e.g. updates.example.com) instead of the root domain for reputation segmentation.

Log in to IONOS

  1. 1
    Open your domain

    Log in at my.ionos.com/domains and choose your domain from the Domain list.

  2. 2
    Open the DNS tab

    Select the DNS tab to reach the page where you manage DNS records.

  3. 3
    Add each record

    Use Add record for every entry below — the DKIM TXT record, the SPF MX and TXT, and the DMARC TXT.

IONOS’s Name / Host name field expects only the subdomain part — enter mailblastr._domainkey, send, and _dmarc, never the full …example.com.

DKIM — TXT

Add one TXT record holding your domain’s DKIM public key. Copy the value from your domain configuration page in MailBlastr.

DKIM — TXT
TypeTXToptional

A single DKIM key record.

Host namemailblastr._domainkeyoptional

IONOS appends .example.com, giving mailblastr._domainkey.example.com. mailblastr is the fixed selector MailBlastr uses.

Points tov=DKIM1; k=rsa; p=<public key>optional

The DKIM key record holding your domain’s public key.

TTL1 houroptional

IONOS default.

SPF — MX on the send subdomain

MailBlastr uses the custom MAIL FROM subdomain send.example.com. Select MX, set Name to send, and paste the MailBlastr MX value into Points to.

SPF — MX
TypeMXoptional

Receives bounce and complaint feedback for the MAIL FROM subdomain.

Namesendoptional

Resolves to send.example.com.

Points tofeedback-smtp.us-east-1.amazonses.comoptional

Region-specific feedback host. Replace us-east-1 with your domain’s region.

Priority10optional

IONOS default. Use 20/30 if 10 is already taken on that host.

TTL1 houroptional

IONOS default.

SPF — TXT on the send subdomain

SPF — TXT
TypeTXToptional

SPF policy for the MAIL FROM subdomain.

Host namesendoptional

Same host as the MX — resolves to send.example.com.

TXT valuev=spf1 include:amazonses.com ~alloptional

Authorizes Amazon SES for the MAIL FROM subdomain.

TTL1 houroptional

IONOS default.

DMARC — TXT on _dmarc

DMARC — TXT
TypeTXToptional

DMARC policy record.

Host name_dmarcoptional

Resolves to _dmarc.example.com.

TXT valuev=DMARC1; p=none;optional

A monitoring policy to start with. See Implementing DMARC.

TTL1 houroptional

IONOS default.

IONOS gotchas: enter only the bare Name / Host name prefix (send, _dmarc, mailblastr._domainkey), never the full domain; and never reuse an existing MX priority on the same host.

Once all six records are saved, return to MailBlastr and re-verify the domain. If it stays pending, see What if my domain isn’t verifying?.