When integrating Sign in with Apple in your app, there are a few extra steps required if you’re sending emails. This is because Apple’s Private Email Relay feature lets users create anonymous email addresses, and Apple enforces stricter requirements to prevent spam.
To ensure your emails are successfully delivered through Apple’s relay service, you’ll need to add an SPF record for Postmark (our email sending gateway).
Normally, Postmark doesn’t require SPF records for email delivery. However, Apple’s Private Email Relay does require SPF.
Add the following SPF record to your domain’s DNS:
v=spf1 include:spf.mtasv.net ~all