How To Add An Authorized Email Address
Sending emails with the MailPoet Sending Service requires you to use an email address that belongs to you for all accounts starting on March 1st 2019.
This is a basic security measure to avoid phishing. For example, you are not allowed to use firstname.lastname@example.org, unless you own this address of course.
You can add the email addresses in your account in just a few minutes, on this page:
Once you have authorized your email address(es), ensure that you update your Settings. See guide.