Domain Authentication Impact from Apple iOS 13

Apple iOS 13 includes “Sign in with Apple” Oauth feature which provides an optional private relay email for users and sender authentication requirements for Apple app developers. In order to send email to Apple Oauth private relay email addresses (@privaterelay.appleid.com), you will need to update your Domain Authentication settings within your SendGrid account. Failure to properly complete and register your SendGrid Domain Authentication with Apple will result in email sent to “privaterelay.appleid.com” returning a bounce event with the reason “550 5.1.1 bad mailbox name.” Visit this blog post for step-by-step instructions.