In most cases, email issues can be resolved by reviewing the Email setup guide and making sure your DNS records are setup correctly.

If you are not using OneSignal Email and instead integrating with SendGrid, Mailchimp, or Mailgun directly, then you may have limits on how many messages you can send each month. Make sure you are sending within your monthly plan allowance! You can check your ESP logs for more details.

Deliverability issues

These include issues like emails not sending, not displaying, and going automatically going to spam. Please make sure to review the Email deliverability guide before continuing.

Not receiving emails

The message shows sent from OneSignal but not displaying in my inbox!

Same sending and receiving domain

An email server can only send or receive emails from a given domain. It cannot do both. When you configured your DNS records with OneSignal, the MX records are used for the same domain you are sending FROM.

For example, you cannot send emails from @mydomain.com and receive emails on an @mydomain.com address unless you point the MX records to a different email server.

If you want to receive emails from the same domain you are sending from, you will need to point your MX records to a different email server. An example of this would be to setup your Google Apps Workspace MX Records.

Multiple TXT records for sending domain

You cannot have more than 1 sender policy for your sending domain. Visit https://www.whatsmydns.net/#TXT and add your sender domain. Check that you do not see multiple entries.

Suppression lists

The email address you are sending TO may have unsubscribed or marked your domain as spam. In either case, it might be on your ESP's Suppression List. To make sure this is not the case, navigate to your OneSignal Audience > Subscriptions tab and search for the email address. Next to the record, select "Resubscribe to Email". You may need to select "Unsubscribe from Email" first, then "Resubscribe to Email" to make sure the record is removed from the ESP Suppression List. Then send it an email to verify it is sent.

Blocked OneSignal IPs

We recommend allowing HTTPS traffic from api.onesignal.com. You can use IP blocking, but we use GCP data centers located in Groningen, Netherlands. There is a wide range of IPs that can be used and are updated frequently. See REST API overview for details.

API key too restrictive

This is usually an issue for Sendgrid and Mailchimp. Check the setup guides for details.

Emails landing in spam

The most common reason for emails landing in spam folder is due to poor reputation which can result from a multitude of factors. Make sure you follow the Email deliverability guide to reduce spam reports.

If not using OneSignal email, then you will also want to work with your Email Service Provider to figure out which deny list you are on, and then work with the specific ISPs to get removed from their lists. Here are some helpful policies and procedures from our supported ESPs:

Apple Private Relay emails

If you are collecting and sending to Apple private relay emails, you will need to verify your sending domain with your Apple developer account.

Failing to verify your domain within the Apple developer account will lead to dropped emails.

For instructions on how to configure your DNS for Apple Private Relay, you can go to Apple's setup guide to Configure Private Relay Email Service.

Email design

Issues that may come up with elements in the email itself.

URLs not working

This usually happens if your CNAME record is not setup correctly. However, if you are not using OneSignal email, then your ESP may have other configurations that need to be setup.

Buttons not clickable

Make sure that your button has a correctly spelled (includes https://) and working URL specified for it in your email's design. Also, ensure that you're not viewing the email from inside your email client's Spam folder, as the email client may block all link clicks automatically.

How do I add images to my pre-header?

Gmail allows for images in the preheader aka Deal Annotations and Product Carousels within the Promotions tab. Details can be found on Google's Gmail Developer Portal.

Email Service Providers (ESPs)

Common questions or issues related to using our integrations with SendGrid, Mailchimp, or Mailgun.

Do I have to pay another provider for email?

If you use the OneSignal Email Setup then we will manage your email accounts and you do not need to use another email provider. If you plan to use Sendgrid, Mailchimp, or Mailgun, then you will need to continue to pay your email service provider directly.

How do I set up email webhooks?

We provide Event Streams which are our version of webhooks. You may want to point your ESP's webhooks to OneSignal and use Event Streams to point to your 3rd party URLs. For more options, see ESP webhooks & email stats.

What is OneSignal's email throughput?

OneSignal generally sends messages at a rate of 1,000 to 5,000 per second to the Email Service Provider. It is up to your ESP to deliver the emails to your users.

OneSignal uses Mailgun for OneSignal Email and Mailgun advertises that they can support up to 15 million emails per hour.