Umbraco-CMS/src/Umbraco.Core/Configuration/Models/SmtpSettings.cs

using System.ComponentModel.DataAnnotations;
using System.Net.Mail;
using Umbraco.Core.Configuration.Models.Validation;

namespace Umbraco.Core.Configuration.Models
{
    public class SmtpSettings : ValidatableEntryBase
    {
        [Required]
        [EmailAddress]
        public string From { get; set; }

        public string Host { get; set; }

        public int Port { get; set; }

        public string PickupDirectoryLocation { get; set; }

        public SmtpDeliveryMethod DeliveryMethod { get; set; }

        public string Username { get; set; }

        public string Password { get; set; }
    }
}