Our metrics have indicated that for a small percentage of customers, Apple mail services (any email with @icloud.com or @me.com) are consistently blocking emails sent from Clerk or marking them as spam.

We have not seen any pattern around why this happens to some customers and not others, and have no information around why Apple is blocking emails. This appears to apply only to Apple email addresses, not email addresses from any other provider. We are actively investigating and trying to get more information from Apple around how this can be resolved.