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Overview

Email remains one of the most effective channels for direct and personalized communication, helping you build long-term customer relationships at scale. This guide walks you through every step required to configure and send emails with OneSignal—ensuring optimal deliverability and compliance from day one.

Email channel setup overview

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Email setup

In your OneSignal dashboard, navigate to Settings > Email > Set up Email.

Activating Email platform in OneSignal settings

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Select provider

Click Continue Setup to continue with OneSignal Email. We also support external providers:

Email Setup Page

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Create a sender

This step lets OneSignal send authenticated mail from your domain. Set your:
  • Default Sender Email: The default email address used to send messages when no other sender is specified.
  • Default Sender Name: The display name that appears in the recipient’s inbox (e.g. Acme Team, Maggie’s Newsletter).
  • Default Reply-To: The email address users will reply to. You can override this per email if needed.
  • Sending Domain: OneSignal will auto-generate a subdomain based on your Default Sender Email, which you can customize.

Default Sender Email

For optimal deliverability, use a subdomain (e.g., mail.yourdomain.com) rather than your root domain.You can add more senders later in Senders Settings.

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DNS configuration

You must configure DNS records to authenticate your sending domain. There are two options:
  1. Auto-configure your domain (recommended)
  2. Manually configure your domain
When viewing your DNS configuration in the OneSignal dashboard:
  • ⚠️ means the current DNS record does not match
  • ✅ means the current DNS record matches
Use your domain registrar login to configure DNS automatically.This method eliminates manual copying and ensures all required records are added correctly.

DNS Auto-Configure

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Verify your account

Once DNS is set, click the “Verify” button to open a support ticket. You’ll be asked about your company and intended use cases.

Account Verification

  • Provide complete answers to speed up approval.
  • Our Support Team typically responds within 24 business hours.
  • You’ll receive an email when verification is complete.

You can send test emails while you wait!

While you wait, continue with email setup!

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Email sending reputation

Maintaining a healthy email reputation is critical for deliverability. Reputation is assigned by inbox providers and behaves like a credit score. Factors that influence it include:
  • Positive signals: opens, clicks, replies
  • Negative signals: bounces, spam complaints, spam traps
Keep bounce rate < 5% and complaint rate < 0.5%. Higher rates may violate our Acceptable Use Policy.

Email Deliverability

Learn more about email deliverability and how to improve your sending reputation.

Email Reputation Best Practices

Learn how to build and maintain a healthy sending reputation.

Email Auto Warm Up

Gradually warm up your sender to build a healthy reputation.

Suppressions

Automatically suppress problematic recipients.

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Understanding users and subscriptions

Each unique email address is treated as a separate email Subscription in OneSignal. Subscriptions can be created by:
  • Uploading email addresses via CSV
  • Using the API
  • Capturing email addresses with a web prompt
  • Using the SDK’s addEmail method
Email addresses are unique per app and considered anonymous until you assign them an External ID.

Users

Manage users, assign External IDs, and track activity.

Subscriptions

Learn how subscriptions work across devices.

Segments

Target users based on behavior and traits.

Upload CSV

Bulk upload email addresses to create subscribers.

Create User/Subscription APIs

Use APIs to manage email users.

Web Prompt

Prompt users to input their email address.

Email SDK Methods

Programmatically add or remove email subscribers.

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Design emails

Design and personalize responsive emails using OneSignal’s editor or HTML.

Design Emails with Drag and Drop

Use the drag-and-drop editor for fast visual design.

Design Emails with HTML

Use custom HTML to design your own templates.

Email Template Forwarding

Forward email templates to a specific address.

Create Template

Create and manage templates via API.

AB Test

Test variants to improve email performance.

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Message personalization and localization

Customize messages using user data and language preferences.

Message Personalization

Use dynamic variables like name or location.

Multi-Language Messaging

Send messages in users’ preferred language.

Dynamic Content

Personalize content in real time using user data.

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Configure email behavior

Before launching campaigns, configure behavior settings:

URLs, Links, and Deep Linking

Set up links and support deep linking.

Email unsubscribe links

Customize unsubscribe behavior.

Custom unsubscribe page

Brand and extend your unsubscribe page.

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Analytics and troubleshooting

Measure and optimize your email performance.

Email message reports

View delivery, open, and click metrics.

Analytics overview

Explore analytics across all channels.

Email Troubleshooting

Find solutions to common setup issues.
Congratulations! Your Email setup is complete.Next steps:
  • Journeys: Build automated messaging flows
  • Tags: Add user-level data for targeting
  • Analytics: Track engagement and conversion metrics