DMARC & Sender Email Address

DMARC stands for Domain-based Message Authentication, Reporting & Conformance. It is a protocol used to validate the authenticity of an email message by verifying the sender's identity. It is an important security measure that helps protect the reputation of a domain and its associated email messages. It is important to ensure that the DMARC configuration is set up correctly for all sender email addresses.


For sending with OneSignal mail only

DMARC configuration only applies to OneSignal mail. If sending through an ESP like, Mailgun, Mailchimp, or SendGrid. You are responsible for ensuring your sender email address matches the domain configured in your ESP.

DMARC Settings

DMARC configuration issues can cause problems with the delivery of email messages. If an email address is not properly configured, the email message may be blocked or marked as spam. This can lead to a decrease in deliverability and a decrease in the reputation of the sender's domain. It is important to understand the process for adding a sender to ensure that the DMARC configuration is properly set up.

There are several different DMARC configurations that can be used, depending on the desired outcome. For example, the "p=reject" configuration will cause any messages that fail authentication to be rejected, while the "p=quarantine" configuration will cause them to be quarantined and potentially marked as spam.

Both "p=reject" and "p=quarantine" help prevent unwanted parties from sending emails from your sending domain. Unfortunately, these settings might prevent you from sending emails on OneSignal if you haven't added your domain to OneSignal by completing the DNS Authentication process.

If the DMARC is configured to "p=none" or no configuration is set, you can use that domain as you in the sender 'from address' to send emails.

DMARC Alerts

If you see the warning in OneSignal, this means that you have a "p=reject" or "p=quarantine' flag configured on the sender email address provided. You won't be able to send the email from the provided address with either configuration.


How to Resolve

To resume sending, you have 3 options:

  1. Choose a different sender email address. You can pick a sender address that does not have any DMARC configuration.
  2. Authenticate your sending domain. Setup a Custom Sender Domain to ensure that the root of the domain you configure matches your sending email address.
    For example, you can configure as your sending domain. And send emails from [email protected].
  3. Update the DMARC config for your sender email address. To do this, open the DMARC settings in your DNS configuration, and change the p flag from "p=regect" or "p=quarantine" to "p=none".