public void NotValidEmail()
        {
            //Arrange
            var mailDetails = new MailDetails();
            const string mailAddress = "john.smith.company.com";

            //Act
            bool isValid = mailDetails.IsValidAddress(mailAddress);

            //Assert
            Assert.False(isValid, $"The email {mailAddress} is valid, but it shouldn’t");
        }
        public void CheckEmail(string mailAddress, bool expectedTestResult)
        {
            var mailDetails = new MailDetails();

            Assert.Equal(expectedTestResult, mailDetails.IsValidAddress(mailAddress));
        }