MessageType: "OrderDeclined" | "OrderSubmitted" | "ShipmentCreated" | "ForgottenPassword" | "ForgottenUsername" | "OrderSubmittedForYourApproval" | "OrderSubmittedForApproval" | "OrderApproved" | "OrderSubmittedForYourApprovalHasBeenApproved" | "OrderSubmittedForYourApprovalHasBeenDeclined" | "NewUserInvitation" | "OrderReturnDeclined" | "OrderReturnSubmitted" | "OrderReturnSubmittedForYourApproval" | "OrderReturnSubmittedForApproval" | "OrderReturnApproved" | "OrderReturnSubmittedForYourApprovalHasBeenApproved" | "OrderReturnSubmittedForYourApprovalHasBeenDeclined" | "OrderReturnCompleted" | "SubscriptionReminder" | "ProductCollectionInvitationAccepted" | "ProductCollectionInvitationDeclined"