How to Set Up IONOS DNS Records for Email Marketing

You manage DNS records in IONOS through the Domains & SSL section of your Cloud Panel or account dashboard. IONOS defaults to a TTL of 1 hour (3600 seconds). Before adding email marketing records, check for existing SPF or MX entries so you do not overwrite active business mail configurations.

IONOS DNS navigation and nameserver check

To access your DNS records in IONOS:

1. Log in to the IONOS Control Panel.
2. In the main navigation, click Domains & SSL.
3. Locate your domain name, click the gear icon (or the Actions menu), and select DNS.

Before adding records, check the Nameserver section on your domain settings page. Your domain must point to IONOS nameservers (such as ns1017.ui-dns.com and ns1017.ui-dns.org). If your domain uses custom external nameservers, changes made in IONOS will not resolve. In that case, add your records in the external provider’s control panel.

Adding a record in IONOS

1. On the domain DNS page, click Add record.
2. Select the record type from the list (TXT, CNAME, or MX).
3. Fill in the Host name field:
   • For root domain records (such as SPF), enter @.
   • For subdomains (such as _dmarc or DKIM selectors), enter only the prefix. IONOS appends your root domain automatically.
4. Enter the destination value:
   • For TXT records, paste the plain text string into the Value field. Do not wrap the value in quotation marks.
   • For CNAME records, enter the destination hostname into the Points to field.
   • For MX records, enter the mail server hostname into the Points to field, and select or type your priority integer in the Priority field.
5. Select your TTL (the default 1 hour works well for most setups).
6. Click Save.

IONOS explains its DNS settings and management options in its DNS record overview.

Required authentication records

Receiving mail servers use these three records to verify that messages sent from your domain are authentic.

1. SPF (Sender Policy Framework)

• Type: TXT
• Host name: @
• Value: The SPF string provided by your email platform, such as:

  v=spf1 include:_spf.google.com include:sendgrid.net ~all

• TTL: 1 hour

Merging multiple SPF records

A domain must only have one root SPF record. If you use IONOS Mail, IONOS may have generated an existing SPF record (v=spf1 include:_spf-eu.ionos.com ~all or similar).

Do not add a second TXT record starting with v=spf1. Multiple SPF records cause receiving mail servers to fail evaluation with a PermError, which sends messages to spam or triggers delivery rejections.

To update an existing SPF record:

1. In the DNS records table, find the existing TXT record starting with v=spf1.
2. Click the gear icon next to that record and select Edit record.
3. Insert your email marketing provider’s include: mechanism before the closing qualifier (~all or -all). For example:

   v=spf1 include:_spf-eu.ionos.com include:sendgrid.net ~all

4. Click Save.

Do not add quotation marks around the string in the Value field. IONOS stores text values literally.

2. DKIM (DomainKeys Identified Mail)

Email providers supply DKIM records in either CNAME or TXT format:

CNAME-based DKIM

Most modern email platforms (such as Klaviyo, Postmark, SendGrid, and Amazon SES) use CNAME records:

• Type: CNAME
• Host name: The selector prefix without your domain, such as s1._domainkey
• Points to: The target hostname provided by your email platform, such as s1.domainkey.example-esp.com
• TTL: 1 hour

If your email provider provides a full hostname like s1._domainkey.yourdomain.com, enter only s1._domainkey in the Host name field. Entering the full domain causes IONOS to publish s1._domainkey.yourdomain.com.yourdomain.com, which breaks DKIM verification.

TXT-based DKIM

Some platforms provide a raw public key string:

• Type: TXT
• Host name: The selector prefix, such as google._domainkey
• Value: The raw public key string starting with v=DKIM1; k=rsa; p=...
• TTL: 1 hour

Paste the full public key directly into the Value field without quotation marks.

3. DMARC (Domain-based Message Authentication, Reporting, and Conformance)

• Type: TXT
• Host name: _dmarc (IONOS attaches your root domain automatically)
• Value:

  v=DMARC1; p=none; rua=mailto:dmarc-reports@yourdomain.com; pct=100;

• TTL: 1 hour

Start with p=none to collect delivery reports without risking inbox delivery. Once SPF and DKIM authenticate consistently across all your sending services, update the policy tag to p=quarantine or p=reject.

Optional deliverability and branding records

These records configure custom subdomains for bounce management and click tracking.

4. Custom return path (bounce domain) (optional)

• Type: CNAME
• Host name: bounces (or the subdomain prefix specified in your platform settings)
• Points to: The mail server hostname assigned by your email platform (such as pm.mtasv.net)
• TTL: 1 hour

5. Branded tracking domain (optional)

• Type: CNAME
• Host name: links (or track, click, or email as specified by your platform)
• Points to: The tracking hostname assigned by your email platform
• TTL: 1 hour

Setting up custom MX records (if required)

If your email marketing service requires dedicated MX records for inbound message processing, reply handling, or sending subdomains:

1. On the DNS management page, click Add record and choose MX.
2. Enter the details:
   • Host name: @ for the root domain, or mail for a dedicated sending subdomain.
   • Points to: The mail server address provided by your platform (such as feedback-smtp.us-east-1.amazonses.com).
   • Priority: The integer specified by your provider (such as 10).
   • TTL: 1 hour
3. Click Save.

If you use IONOS Mail or Google Workspace for your business mailboxes, do not overwrite your root MX records. Replacing root MX records pointing to IONOS mail servers (mx00.ionos.com and mx01.ionos.com) deactivates inbound mail for all connected IONOS mailboxes. Only add MX records for dedicated subdomains unless you are permanently migrating your primary inbox service.

Verifying your DNS records

IONOS updates take effect within 1 hour globally. You can verify your DNS records in Windows PowerShell using Resolve-DnsName:

Check SPF

Resolve-DnsName -Name yourdomain.com -Type TXT

Review the Strings column. Verify that only one SPF record exists and that your sending service mechanism is listed.

Check DMARC

Resolve-DnsName -Name _dmarc.yourdomain.com -Type TXT

Confirm that the output contains your v=DMARC1; p=... record.

Check DKIM

Replace s1 with your provider’s specific selector:

Resolve-DnsName -Name s1._domainkey.yourdomain.com -Type CNAME

If your platform uses TXT-based DKIM, change -Type CNAME to -Type TXT. The output will display your provider’s target hostname or public key.

Check tracking and bounce records (if configured)

Resolve-DnsName -Name bounces.yourdomain.com -Type CNAME

The NameHost column should point to your email platform’s destination address.

Check MX records (if configured)

Resolve-DnsName -Name yourdomain.com -Type MX

The NameExchange column should list your designated mail servers with their numerical priorities under Preference.

Common troubleshooting issues

Issue	Root cause	Solution
Subdomain hostname is duplicated (_dmarc.yourdomain.com.yourdomain.com)	The full domain was typed into the Host name field.	Enter only the subdomain prefix (such as _dmarc). IONOS appends your domain automatically.
SPF status shows PermError	Multiple TXT records start with v=spf1.	Edit the existing SPF record, merge all include: mechanisms into that single record, and delete any duplicate entries.
Verification fails with syntax error	Quotation marks were pasted into the Value field.	Remove surrounding quotes from the Value field. IONOS handles text formatting automatically.
IONOS mailboxes stop receiving email	Root MX records pointing to IONOS mail servers were replaced.	Restore the original IONOS MX records, and configure marketing MX records on a dedicated sending subdomain.
Records do not resolve externally	The domain uses external nameservers.	Check the Nameservers section in the IONOS dashboard. If external nameservers are active, configure DNS records at that external provider.