Emails Not Delivered

Troubleshooting why emails sent from OneSignal are not delivered to your inbox.

If email is configured correctly within your OneSignal dashboard, then email requests should be going from OneSignal to an Email Service Provider (ESP) who then delivers the emails to your users.

Common Issues When Not Using OneSignal Email

If you are using your own ESP and not using OneSignal's Email, then your ESP may have limits on how many messages you can send each month. Make sure you are sending within your monthly plan allowance.

If the ESP is having any API issues, that would also affect your sending and you will need to retry once they are back online. Status pages: OneSignal, Mailgun, SendGrid, Mailchimp

Please check these items are correct before moving forward.

Common Reasons Emails Do Not Display

Not Receiving On Sending 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 and receive emails on an 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.

The To/From Email Address

Check that you are sending TO a valid email address. Also, make sure you are sending FROM an email address with a valid domain. If your ESP is set to use but you send from that could be blocking the message from being delivered.

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.

Multiple TXT records for sending domain

You cannot have more than 1 sender policy for your sending domain. Visit and add your sender domain. Check that you do not see multiple entries.

Blocking OneSignal IPs

OneSignal uses GCP data centers located in Groningen, Netherlands. There are a wide range of IPs that can be used. If you are strict with your IP management, make sure to whitelist the following (make sure to include your own IP Address if you have not!):,,,,,,,,,,,,2600:1900:4060::/44

API Key is too Restrictive

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

Check The Logs

Each ESP provides activity logs which help detect any errors that might occur along the way. Please see the below steps to access your logs. If stuck, contact support directly or email [email protected] with the following details:

  • Your OneSignal App Id
  • A .txt file or screenshot of the logs with the error code like in the screenshots provided below


In your MailGun Account under Sending > Logs, search the dates you sent the email. Click the email and check the delivery-status > description and error code for more details.


Status Message: unable to connect to MX servers:

This means Mailgun tried to contact the mail server for that email address, but the MX server did not respond. You may be on a lower tier plan with Mailgun and need to upgrade or have a configuration error for the MX record, check your DNS settings to make sure it is set up correctly.


In your SendGrid Account under Activity, search the dates you sent the email.

Click the error email. If you see the issue with SendGrid, see the SendGrid Troubleshooting for details.

If you see the error with OneSignal, click the date to expand the error. In the section "Full response from the server:" this will hint at the area that is broken.


Within your Mailchimp Transactional Email Dashboard (formerly Mandrill), navigate to Outbound > Activity screen.

Here you will see the "Status" is "Rejected". By clicking this, you can see why.