If you're using Amazon SES and emails to @privaterelay.appleid.com are silently failing, the cause is almost certainly SES's account-level suppression list treating Apple relay DSN errors as hard bounces. Fix: Emails Not Delivered to Apple Private Relay Addresses (Amazon SES) If your app supports Sign in with Apple , some of your users will have a Hide My Email address — a relay address like abc123@privaterelay.appleid.com that forwards to their real inbox. These addresses are easy to break silently. Here's the symptom we ran into and exactly how we fixed it. The Symptom Transactional emails (alerts, welcome emails) worked fine for regular email addresses but never arrived for users who signed in with Apple.…