/// <summary>
        /// Runs based on the specified options.
        /// </summary>
        /// <param name="options">The options.</param>
        /// <returns>
        /// The program return code
        /// </returns>
        private static int Run(Options options)
        {
            if (!options.LoadSettingsFile())
            {
                Console.Error.WriteLine(string.Format(OptionsExtensions.FileDoesNotExist, options.SettingsFile));
                return(INVALID_RUN);
            }

            string error = options.Validate();

            if (!string.IsNullOrEmpty(error))
            {
                Console.Error.WriteLine(error);
                return(INVALID_ARGUMENTS);
            }

            IServiceProvider serviceProvider = InitDependencyInjection(options);
            IEmailHandler    handler         = serviceProvider.GetRequiredService <IEmailHandler>();

            if (!handler.HandleIncomingEmail())
            {
                return(INVALID_RUN);
            }

            return(VALID_RUN);
        }