MailKit发送邮件

背景

由于smtpClient发送邮件偶发出现超时的情况，而且4.7版本后被标志为已过时，故换成MailKit方式。
https://docs.microsoft.com/en-us/dotnet/api/system.net.mail.smtpclient?view=netframework-4.7.1

MailKit源码地址：https://github.com/jstedfast/MailKit

实现

示例demo地址：MailKitDemo

1、引包

创建MailKitDemo项目，安装nuget包，示例版本是3.1.1

2、MailHelper

封装MailHelper方法类，提供连接、授权、日志等操作。

public static class MailHelper
{
    /// <summary>
    /// 发送邮件
    /// </summary>
    /// <param name="mailBodyEntity">邮件基础信息</param>
    /// <param name="sendServerConfiguration">发件人基础信息</param>
    public static SendResultEntity SendMail(MailBodyEntity mailBodyEntity,
        SendServerConfigurationEntity sendServerConfiguration)
    {
        if (mailBodyEntity == null)
        {
            throw new ArgumentNullException();
        }
 
        if (sendServerConfiguration == null)
        {
            throw new ArgumentNullException();
        }
 
        var sendResultEntity = new SendResultEntity();
 
        using (var client = new SmtpClient(new ProtocolLogger(MailMessage.CreateMailLog())))
        {
            client.ServerCertificateValidationCallback = (s, c, h, e) => true;
 
            Connection(mailBodyEntity, sendServerConfiguration, client, sendResultEntity);
 
            if (sendResultEntity.ResultStatus == false)
            {
                return sendResultEntity;
            }
 
            SmtpClientBaseMessage(client);
 
            // Note: since we don't have an OAuth2 token, disable
            // the XOAUTH2 authentication mechanism.
            client.AuthenticationMechanisms.Remove("XOAUTH2");
 
            Authenticate(mailBodyEntity, sendServerConfiguration, client, sendResultEntity);
 
            if (sendResultEntity.ResultStatus == false)
            {
                return sendResultEntity;
            }
 
            Send(mailBodyEntity, sendServerConfiguration, client, sendResultEntity);
 
            if (sendResultEntity.ResultStatus == false)
            {
                return sendResultEntity;
            }
            client.Disconnect(true);
        }
        return sendResultEntity;
    }
 
 
    /// <summary>
    /// 连接服务器
    /// </summary>
    /// <param name="mailBodyEntity">邮件内容</param>
    /// <param name="sendServerConfiguration">发送配置</param>
    /// <param name="client">客户端对象</param>
    /// <param name="sendResultEntity">发送结果</param>
    private static void Connection(MailBodyEntity mailBodyEntity, SendServerConfigurationEntity sendServerConfiguration,
        SmtpClient client, SendResultEntity sendResultEntity)
    {
        try
        {
            client.Connect(sendServerConfiguration.SmtpHost, sendServerConfiguration.SmtpPort);
        }
        catch (SmtpCommandException ex)
        {
            sendResultEntity.ResultInformation = $"尝试连接时出错:{0}" + ex.Message;
            sendResultEntity.ResultStatus = false;
        }
        catch (SmtpProtocolException ex)
        {
            sendResultEntity.ResultInformation = $"尝试连接时的协议错误:{0}" + ex.Message;
            sendResultEntity.ResultStatus = false;
        }
        catch (Exception ex)
        {
            sendResultEntity.ResultInformation = $"服务器连接错误:{0}" + ex.Message;
            sendResultEntity.ResultStatus = false;
        }
    }
 
    /// <summary>
    /// 账户认证
    /// </summary>
    /// <param name="mailBodyEntity">邮件内容</param>
    /// <param name="sendServerConfiguration">发送配置</param>
    /// <param name="client">客户端对象</param>
    /// <param name="sendResultEntity">发送结果</param>
    private static void Authenticate(MailBodyEntity mailBodyEntity, SendServerConfigurationEntity sendServerConfiguration,
        SmtpClient client, SendResultEntity sendResultEntity)
    {
        try
        {
            client.Authenticate(sendServerConfiguration.SenderAccount, sendServerConfiguration.SenderPassword);
        }
        catch (AuthenticationException ex)
        {
            sendResultEntity.ResultInformation = $"无效的用户名或密码:{0}" + ex.Message;
            sendResultEntity.ResultStatus = false;
        }
        catch (SmtpCommandException ex)
        {
            sendResultEntity.ResultInformation = $"尝试验证错误:{0}" + ex.Message;
            sendResultEntity.ResultStatus = false;
        }
        catch (SmtpProtocolException ex)
        {
            sendResultEntity.ResultInformation = $"尝试验证时的协议错误:{0}" + ex.Message;
            sendResultEntity.ResultStatus = false;
        }
        catch (Exception ex)
        {
            sendResultEntity.ResultInformation = $"账户认证错误:{0}" + ex.Message;
            sendResultEntity.ResultStatus = false;
        }
    }
 
    /// <summary>
    /// 发送邮件
    /// </summary>
    /// <param name="mailBodyEntity">邮件内容</param>
    /// <param name="sendServerConfiguration">发送配置</param>
    /// <param name="client">客户端对象</param>
    /// <param name="sendResultEntity">发送结果</param>
    private static void Send(MailBodyEntity mailBodyEntity, SendServerConfigurationEntity sendServerConfiguration,
        SmtpClient client, SendResultEntity sendResultEntity)
    {
        try
        {
            client.Send(MailMessage.AssemblyMailMessage(mailBodyEntity));
        }
        catch (SmtpCommandException ex)
        {
            switch (ex.ErrorCode)
            {
                case SmtpErrorCode.RecipientNotAccepted:
                    sendResultEntity.ResultInformation = $"收件人未被接受:{ex.Message}";
                    break;
                case SmtpErrorCode.SenderNotAccepted:
                    sendResultEntity.ResultInformation = $"发件人未被接受:{ex.Message}";
                    break;
                case SmtpErrorCode.MessageNotAccepted:
                    sendResultEntity.ResultInformation = $"消息未被接受:{ex.Message}";
                    break;
            }
            sendResultEntity.ResultStatus = false;
        }
        catch (SmtpProtocolException ex)
        {
            sendResultEntity.ResultInformation = $"发送消息时的协议错误:{ex.Message}";
            sendResultEntity.ResultStatus = false;
        }
        catch (Exception ex)
        {
            sendResultEntity.ResultInformation = $"邮件接收失败:{ex.Message}";
            sendResultEntity.ResultStatus = false;
        }
    }
 
    /// <summary>
    /// 获取SMTP基础信息
    /// </summary>
    /// <param name="client">客户端对象</param>
    /// <returns></returns>
    private static MailServerInformation SmtpClientBaseMessage(SmtpClient client)
    {
        var mailServerInformation = new MailServerInformation
        {
            Authentication = client.Capabilities.HasFlag(SmtpCapabilities.Authentication),
            BinaryMime = client.Capabilities.HasFlag(SmtpCapabilities.BinaryMime),
            Dsn = client.Capabilities.HasFlag(SmtpCapabilities.Dsn),
            EightBitMime = client.Capabilities.HasFlag(SmtpCapabilities.EightBitMime),
            Size = client.MaxSize
        };
 
        return mailServerInformation;
    }
}

主程序调用

static void Main(string[] args)
{
    
    var mailServerConfig = new SendServerConfigurationEntity()
    {
        SmtpPort = 0,                           //SMTP端口
        IsSsl = true,                           //启用Ssl
        SenderAccount = "****@qq.com",     //发件人
        SmtpHost = "smtp.qq.com",               //邮件Smtp服务，QQ：smtp.qq.com
        SenderPassword = "****",    //邮箱授权码
    };
    
    var mailBodyEntity = new MailBodyEntity()
    {
        Subject = "标题",
        Body = "邮件内容：<BR>百度：<a href='http://www.baidu.com'>点我</a>",
        Recipients = new List<string>() { "***@163.com"},      //收件人
        SenderAddress = "****@qq.com",     //发件人
    };
    var result = MailHelper.SendMail(mailBodyEntity, mailServerConfig);
    
}

配置项UI如下：

3、效果及日志

日志：

邮件服务配置

1、网易个人/VIP邮箱

开启SMTP服务

该授权码对应 EmailRequest中的Password
网易个人邮箱/VIP邮箱的smtp地址：smtp.163.com
网易个人邮箱/VIP邮箱的smtp端口: 465

2、网易企业邮箱

网易企业邮箱不需要生成授权码，Password使用邮箱的登录密码即可
网易企业邮箱的smtp：smtp.ym.163.com
网易企业邮箱的smtp端口号：465
注意：网易企业邮箱的smtp不一定是smtp.ym.163.com，可以参考：https://qiye.163.com/help/client-profile.html

3、outlook个人邮箱

outlook个人邮箱smtp服务器是：smtp-mail.outlook.com
outlook个人邮箱smtp端口号是：587
Password是登录outlook邮箱的密码

4、QQ个人邮箱

QQ个人邮箱的流程类似网易个人邮箱，都需要生成授权码

QQ个人邮箱的smtp地址是：smtp.qq.com
QQ个人邮箱的smtp端口号是：465
QQ个人邮箱的Password是上面的申请的授权码