Hi @sjoerddk ,
Welcome to the Auth0 Community!
If the Sendgrid indicates they are delivered, that means the email was sent successfully from Auth0 to Sendgrid. Have you checked the spam folder?
Also, I suggest you check Auth0 tenant logs to make sure no failure in sending the emails to Sendgrid.
This FAQs talked about email delivery issues. Hopefully, it’s helpful to you!
I am happy to look deeper into this if you can DM me the name of the tenant and the sample user email.
Thanks!