public async Task SendNewEmailAddressApprovalEamilHandlerInvokesSendEmailAsyncWithTheCorrectParameters() { var message = new SendNewEmailAddressConfirmationEmail { Email = "email", CallbackUrl = "CallbackUrl" }; var emailMessage = $"Please confirm your new email address for your allReady account by clicking this link: <a href=\"{message.CallbackUrl}\">link</a>. Note that once confirmed your original email address will cease to be valid as your username."; var emailSender = new Mock<IEmailSender>(); var sut = new SendNewEmailAddressConfirmationEmailHandler(emailSender.Object); await sut.Handle(message); emailSender.Verify(x => x.SendEmailAsync(message.Email, "Confirm your allReady account", emailMessage)); }