PayPal is upgrading the certificate for www.paypal.com to SHA-256. This endpoint is also used by merchants using the Instant Payment Notification (IPN) product.
This upgrade is scheduled for 9/30/2015 however, we may need to change this date on short notice to you to align to the industry security standard.
You’re receiving this notification because you’ve been identified as a merchant who has used IPN endpoints within the past year. If you have not made the necessary changes, we urge you to do so right away to avoid a disruption of your service!
Because these changes are technical in nature, we advise that you consult with your individuals responsible for your PayPal integration. They will be able to identify what, if any, changes are needed. Please share this email and the hyperlinks below with your technical contact for evaluation.
Testing in the Sandbox is one of the best ways to make sure your integration works. Sandbox endpoints have been upgraded to accept secure connections by the SHA-256 Certificates.