Apparently the NotificationService and the AuthenticationController use the SendAsync overload that disables the notification handler from being fired. Could anyone explain me why this is? We're using Office365 as an SMTP server which requires OAuth which by default isn't possible within Umbraco. My idea was to create a NotificationHandler for the SendEmailNotification notification, so I do not have to create my own implementation of EmailSender. Would it be better to replace the default EmailSender instead of listening to the SendEmailNotification?