We discovered today that emails sent only from development instances to Apple email addresses (icloud.com, me.com) are being rejected by Apple. We have reached out to Apple to inquire further and are hoping for a swift resolution on their end.

In the meantime, we recommend using test emails (https://clerk.com/docs/guides/development/testing/test-emails-and-phones#email-addresses) or an email address from a non-Apple domain to test/send emails from your development instances.