some users do not receive mail confirmation emails from auth0

We use the standard API, but some users do not receive a confirmation email.
Works on outlook.com, yahoo.com domains. Emails have not been found in spam.

We only found out about this through user complaints.

How can we keep track of the emails that did not receive a confirmation and why this can happen?
Thank you.

Hi @jap125

Welcome to the Auth0 Community!

Thank you for posting your question. Do your auth0 logs show the emails have been sent properly? If that’s the case, you may need to contact the email provider directly, as we can’t control the email as soon as they leave our infrastructure.

Thanks
Dawid