This guide walks you through setting up DNS records provided by OneSignal to authenticate your sending domain. In most cases, DNS can be auto-configured from the OneSignal dashboard as described in the Email Setup guide.

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Requirements

If you need to manually set up your sending domain DNS recordss, you must:
  • Own the sending domain.
  • Have access to DNS settings via your provider.
If you don’t own a domain, you can purchase one via the OneSignal dashboard or register through Cloudflare. This guide will use Cloudflare as an example but most DNS providers work the same.

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Email DNS configuration

Complete the Email Setup steps until you’re prompted to add DNS records, then return here or use the Auto-Configure DNS button. From the OneSignal dashboard:
  • ⚠️ means the current DNS record does not match
  • ✅ means the current DNS record matches
Each DNS record needs to be added to your DNS provider with the exception of the MX record. You must have an MX record, but this may point to a different server.

Copy DNS records from OneSignal

In your DNS provider’s interface (e.g., Cloudflare), go to DNS > Records and add each record. Correctly configuring DNS authentication helps ensure your emails are delivered and not flagged as spam. Here’s a breakdown of the DNS records you will add:

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TXT records

  • Type: TXT
  • Name: OneSignal “Hostname”
  • Content: OneSignal “Value”
  • TTL: Auto or lowest
  • Priority: 10 (if required)
If you already have an SPF TXT record, append additional includes like:v=spf1 include:spf.onesignal.email include:mailgun.org include:your-other-spf-records ~all

DNS record interface

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SPF (Sender Policy Framework)

Verifies the sending IP is authorized to send emails on your domain’s behalf. No extra action needed beyond adding the TXT record provided by OneSignal.

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DMARC

Adds policy enforcement for SPF/DKIM failures. DMARC is required for secure email sending. Learn more: Email Sender Guidelines
OneSignal uses the value v=DMARC1; p=none; for the DMARC record. If you already have a DMARC record, make sure this is included and not set multiple times.

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CNAME records

Used for open, click, and unsubscribe tracking.
  • Type: CNAME
  • Name: OneSignal “Hostname”
  • Target: OneSignal “Value”
  • TTL: Auto or lowest
  • Proxy: DNS only
  • Flattening: Off
  • Priority: 10 (if required)

CNAME record setup

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DKIM (DomainKeys Identified Mail)

Verifies the message’s content was not altered and was sent by you. The public key is included in the DNS record from OneSignal.

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MX records

  • Type: MX
  • Name: OneSignal “Hostname”
  • Mail server: OneSignal “Value”
  • TTL: Auto or lowest
  • Priority: 10

DNS records overview

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MX (Mail Exchange)

Receives email responses or bounces. Even if you’re only sending, these help avoid domain verification errors.
If you already use another email provider (e.g. Gmail), do not overwrite existing MX records.

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DNS verification

After adding records:
  1. Return to the OneSignal dashboard.
  2. Click Check Records.
Verified records show green check marks.

Verified DNS records in OneSignal

Verification typically takes just a few minutes but can take up to 24 hours. Use whatsmydns.net to check propagation if any records are pending.

Check DNS propagation with whatsmydns.net

If verification fails:
  • Confirm the domain is correct.
  • Double-check each record was added exactly as shown in the dashboard.
Return to Email Setup to complete configuration and begin sending emails.