We are a new business and building a system using Auth0. We have multiple instances where Auth0 says it has sent a verification e-mail but non has been received in either spam or main mailbox, seems particularly bad with yahoo destination mailboxes, but others as well. We do not have any real idea of where to start. We are warming the noreply@ e-mail address. any other way we can test / resolve.
Are you using the default Auth0 email infrastructure or have you configured an external provider? I know the default service can be flaky and we definitely encourage using an external provider.
Thanks for confirming - Are you seeing successful signup events in your Auth0 logging (Monitoring → Logs)? I might recommend taking a look at the following FAQ: