[MailKitでメール送受信] #MailKit #Newtonsoft.Json

appSettings.json

{
    "EmailConfiguration": {
        "SmtpServer": "smtp.gmail.com",
        "SmtpPort": 587,
        "SmtpUsername": "yourmailaddress@gmail.com",
        "SmtpPassword": "applicationpassword",
        "PopServer": "pop.gmail.com",
        "PopPort": 995,
        "PopUsername": "yourmailaddress@gmail.com",
        "PopPassword": "yourpassword"
    },
    "EmailMessage": {
        "FromAddress": [
            {
                "Name": "",
                "Address": "sampleFrom@example.com"
            }
        ],
        "ToAddress": [
            {
                "Name": "",
                "Address": "sampleTo@example.com"
            }
        ],
        "Subject": "件名",
        "Content": "メール本文\\nいかがでしょうか。"
    }
}

Config.cs

namespace EmailNet
{
    public class Config
    {
        public EmailConfiguration EmailConfiguration{ get; set; }
        public EmailMessage EmailMessage{ get; set; }
        public EmailAddress EmailAddress { get; set; }
    }
}

EmailAddress.cs

namespace EmailNet
{
    public class EmailAddress
    {
        public string Name { get; set; }
        public string Address{ get; set; }
    }
}

EmailConfiguration.cs

namespace EmailNet
{
    public class EmailConfiguration : IEmailConfiguration
    {
        public string SmtpServer { get; set; }
        public int SmtpPort { get; set; }
        public string SmtpUsername { get; set; }
        public string SmtpPassword { get; set; }

        public string PopServer { get; set; }
        public int PopPort { get; set; }
        public string PopUsername { get; set; }
        public string PopPassword { get; set; }
    }
}

EmailMessage.cs

using System.Collections.Generic;

namespace EmailNet
{
    public class EmailMessage
    {
        public EmailMessage()
        {
            ToAddress = new List<EmailAddress>();
            FromAddress = new List<EmailAddress>();
        }

        public List<EmailAddress> ToAddress { get; set; }
        public List<EmailAddress> FromAddress { get; set; }
        public string Subject { get; set; }
        public string Content { get; set; }
    }
}

EmailService.cs

using System.Collections.Generic;
using System.Linq;
using MailKit.Net.Pop3;
using MailKit.Net.Smtp;
using MailKit.Security;
using MimeKit;
using MimeKit.Text;

namespace EmailNet
{
    public class EmailService : IEmailService
    {
        private readonly IEmailConfiguration _emailConfiguration;

        public EmailService(IEmailConfiguration emailConfiguration)
        {
            _emailConfiguration = emailConfiguration;
        }

        public List<EmailMessage> ReceiveEmail(int maxCount = 10)
        {
            using (var emailClient = new Pop3Client())
            {
                emailClient.Connect(_emailConfiguration.PopServer, _emailConfiguration.PopPort, SecureSocketOptions.SslOnConnect);
                emailClient.Authenticate(_emailConfiguration.PopUsername, _emailConfiguration.PopPassword);

                List<EmailMessage> emails = new List<EmailMessage>();
                for (int i = 0; i < emailClient.Count && i < maxCount; i++)
                {
                    var message = emailClient.GetMessage(i);
                    var emailMessage = new EmailMessage
                    {
                        Content = !string.IsNullOrEmpty(message.HtmlBody)
                                ? message.HtmlBody : message.TextBody,
                        Subject = message.Subject
                    };
                    emailMessage.ToAddress.AddRange(message.To.Select(x => (MailboxAddress)x).Select(x => new EmailAddress { Address = x.Address, Name = x.Name }));
                    emailMessage.FromAddress.AddRange(message.From.Select(x => (MailboxAddress)x).Select(x => new EmailAddress { Address = x.Address, Name = x.Name }));
                }

                emailClient.Disconnect(true);

                return emails;
            }
        }

        public void Send(EmailMessage emailMessage)
        {
            var message = new MimeMessage();
            message.To.AddRange(emailMessage.ToAddress.Select(x => new MailboxAddress(x.Name, x.Address)));
            message.From.AddRange(emailMessage.FromAddress.Select(x => new MailboxAddress(x.Name, x.Address)));

            message.Subject = emailMessage.Subject;

            message.Body = new TextPart(TextFormat.Plain)
            {
                Text = emailMessage.Content
            };

            using (var emailClient = new SmtpClient())
            {
                emailClient.Connect(_emailConfiguration.SmtpServer, _emailConfiguration.SmtpPort, SecureSocketOptions.Auto);
                emailClient.Authenticate(_emailConfiguration.SmtpUsername, _emailConfiguration.SmtpPassword);
                emailClient.Send(message);
                emailClient.Disconnect(true);
            }
        }
    }
}

IEmailConfiguration.cs

namespace EmailNet
{
    public interface IEmailConfiguration
    {
        string SmtpServer { get; }
        int SmtpPort { get; }
        string SmtpUsername { get; set; }
        string SmtpPassword { get; set; }

        string PopServer { get; }
        int PopPort { get; }
        string PopUsername { get; }
        string PopPassword { get; }
    }
}

IEmailService.cs

using System.Collections.Generic;

namespace EmailNet
{
    public interface IEmailService
    {
        void Send(EmailMessage emailMessage);
        List<EmailMessage> ReceiveEmail(int maxCount = 10);
    }
}

Program.cs

using System;
using System.IO;
using Newtonsoft.Json;

namespace EmailNet
{
    class Program
    {
        static void Main(string[] args)
        {
            var config = JsonConvert.DeserializeObject<Config>(LoadSettings());
            var emailService = new EmailService(config.EmailConfiguration);

            if (args[0] == "receive")
            {
                var receiveMessages = emailService.ReceiveEmail(10);
                receiveMessages.ForEach(x =>
                {
                    Console.WriteLine($"From:{x.FromAddress}");
                    Console.WriteLine($"To:{x.ToAddress}");
                    Console.WriteLine($"Subject:{x.Subject}");
                    Console.WriteLine($"Content:{x.Content}");
                });
            }
            if (args[0] == "send")
            {
                var sendMessage = config.EmailMessage;
                emailService.Send(sendMessage);
            }
        }

        private static string LoadSettings()
        {
            var dirName = Directory.GetCurrentDirectory();
            var fileName = @"appSettings.json";

            return File.ReadAllText(Path.Combine(dirName, fileName));
        }
    }
}