1. The message was delivered to the Spam or Trash folder (as you mentioned, this could also be the Promotions tab in Gmail).
2. The patient's email service is filtering or blocking messages from firstname.lastname@example.org.
We recommend the following troubleshooting steps:
1. Ask the patient to search their email account for email@example.com.
2. If they still cannot locate the email, ask the patient to add firstname.lastname@example.org to their Safe Senders list.
You will then need to generate a new registration email for the patient by resetting their patient portal account.