SMTP Provider: Certificate has expired

Dear Auth0 Community,
we are receiving “Failed Sending Notification” errors when issuing Auht0 workflow emails (e.g. password reset email) due to “Certificate has expired” error.

We assume that the certificate that is being checked is either the certificate for the email services (which is and their certificate seems to be just fine) or the certificate of the email sender which is also fine.

We have been using the same configuration for several months and everything has been worked fine. Emails were sent with this configuration in the past.

Could you guys let me know what kind of certificate expiry check is performed and in which particular certificate so we can check with our email providers if is there something wrong with their certificate?

Attached you can find de error message logged in Auth0.

Thank you in advance

We are not receiving the ‘certificate has expired’ error anymore. Don’t know if you have perform any action to solve the problem. We have not contacted our email service provider because we were waiting for your reply. So we cannot guarantee either if they had done something by their side.

Anyway, the error is no longer taking place.


Just to complete the info in case it might help other Auth0 users:

Our application certificate is managed by AWS Certificate Manager (ACM)
This manager automatically renews the certificate.
The certificate has indeed expired yesterday.
Our application site did not shown an expired certificate error or warning message when accessed by Web Browsers.
However, Auth0 SMTP Provider did fail due to Certificate expiration.

There is probabily a period of time between the expiry of the certificate and the automated renewal by AWS Certificate Manager where an expired certificate is used with the Auth0 SMTP Provider. Web Browsers (i.e. Chrome, Edge might use a different policy in handling site certificates and thats why they did not issue an expired certificate error/warning)

1 Like

Thanks for closing the loop on this!

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