.net5 MailKit

MailKit开源地址：https://github.com/jstedfast/MailKit

http://www.mimekit.net/docs/

using System;
using System.IO;
using MailKit.Net.Smtp;
using MimeKit;
using MimeKit.Text;
namespace commom
{
    public class EmailHelper
    {
        //Nuget包管理添加Mailkit
        /// <summary>
        /// 服务邮箱
        /// </summary>
        private string _STEPNAME = "smtp.qq.com";
        /// <summary>
        /// 服务邮箱端口
        /// </summary>
        private int _STEPPORT = 587;
        /// <summary>
        /// 发送方邮箱
        /// </summary>
        private string _USEREMAIL;
        /// <summary>
        /// 发送方邮箱Smtp授权码
        /// </summary>
        private string _PASSWORD;
        /// <summary>
        /// 发送方邮箱归属人，昵称
        /// </summary>
        private string _EMAILBLONGER;
        private string email;
        private string emailBlonger;
        private string smtp;
 
        /// <summary>
        /// 邮箱配置
        /// </summary>
        /// <param name="email"></param>
        /// <param name="smtp"></param>
        public EmailHelper(string email, string smtp)
        {
            this._USEREMAIL = email;
            this._PASSWORD = smtp;
        }
 
        public EmailHelper(string email, string emailBlonger, string smtp)
        {
            this._USEREMAIL = email;
            this._PASSWORD = smtp;
            this._EMAILBLONGER = emailBlonger;
        }
        /// <summary>
        /// 邮箱发送类
        /// </summary>
        /// <param name="toEmaill">发送方邮箱</param>
        /// <param name="toEmailBlonger">发送方名称</param>
        /// <param name="subject">邮件标题</param>
        /// <param name="text">发送的文字内容</param>
        /// <param name="html">发送的html内容</param>
        /// <param name="path">发送的附件,找不到的就自动过滤</param>
        /// <returns></returns>
        public string SendEmail(string toEmaill, string toEmailBlonger, string subject, string text, string html, string path)
        {
            try
            {
                MimeMessage message = new MimeMessage();
                //发送方
                message.From.Add(new MailboxAddress(this._EMAILBLONGER, this._USEREMAIL));
                //接受方
                message.To.Add(new MailboxAddress(toEmailBlonger, toEmaill));
                //标题
                message.Subject = subject;
                //创建附件
                var multipart = new Multipart("mixed");
                //文字内容
                if (!string.IsNullOrEmpty(text))
                {
                    var plain = new TextPart(TextFormat.Plain)
                    {
                        Text = text
                    };
                    multipart.Add(plain);
                }
                //html内容
                if (!string.IsNullOrEmpty(html))
                {
                    var Html = new TextPart(TextFormat.Html)
                    {
                        Text = html
                    };
                    multipart.Add(Html);
                }
                if (!string.IsNullOrEmpty(path))
                {
                    var pathList = path.Split(';');
                    foreach (var p in pathList)
                    {
                        try
                        {
                            if (!string.IsNullOrEmpty(p.Trim()))
                            {
                                var attimg = new MimePart()
                                {//"image", "png"方法里带参数的话
                                    ContentObject = new ContentObject(File.OpenRead(p), ContentEncoding.Default),
                                    ContentDisposition = new ContentDisposition(ContentDisposition.Attachment),
                                    ContentTransferEncoding = ContentEncoding.Base64,
                                    FileName = Path.GetFileName(path)
                                };
                                multipart.Add(attimg);
                            }
                        }
                        catch (FileNotFoundException ex)
                        {
                            //找不到文件就不提交附件了
                        }
                    }
                }
                //赋值邮件内容
                message.Body = multipart;
                //开始发送
                using (var client = new SmtpClient())
                {
                    client.Connect(this._STEPNAME, this._STEPPORT, false);
                    client.Authenticate(this._USEREMAIL, this._PASSWORD);
                    client.Send(message);
                    client.Disconnect(true);
                }
                return "邮件发送成功";
            }
            catch (Exception)
            {
                return "邮箱发送失败";
            }
        }
        /// <summary>
        /// 邮箱发送类，不用输入用户昵称的
        /// </summary>
        /// <param name="toEmaill">发送方邮箱</param>
        /// <param name="toEmailBlonger">发送方名称</param>
        /// <param name="subject">邮件标题</param>
        /// <param name="text">发送的文字内容</param>
        /// <param name="html">发送的html内容</param>
        /// <param name="path">发送的附件，多附件用;隔开</param>
        /// <returns></returns>
        public void SendEmail(string toEmaill, string subject, string text, string html, string path)
        {
            try
            {
                MimeMessage message = new MimeMessage();
                //发送方
                message.From.Add(new MailboxAddress(this._USEREMAIL));
                //接受方
                message.To.Add(new MailboxAddress(toEmaill));
                //标题
                message.Subject = subject;
                //创建附件
                var multipart = new Multipart("mixed");
                //文字内容
                if (!string.IsNullOrEmpty(text))
                {
                    var plain = new TextPart(TextFormat.Plain)
                    {
                        Text = text
                    };
                    multipart.Add(plain);
                }
                //html内容
                if (!string.IsNullOrEmpty(html))
                {
                    var Html = new TextPart(TextFormat.Html)
                    {
                        Text = html
                    };
                    multipart.Add(Html);
                }
                if (!string.IsNullOrEmpty(path))
                {//修改为多附件，
                    var pathList = path.Split(';');
                    foreach (var p in pathList)
                    {
                        try
                        {
                            if (!string.IsNullOrEmpty(p.Trim()))
                            {
                                var attimg = new MimePart()
                                {//"image", "png"方法里带参数的话
                                    ContentObject = new ContentObject(File.OpenRead(p), ContentEncoding.Default),
                                    ContentDisposition = new ContentDisposition(ContentDisposition.Attachment),
                                    ContentTransferEncoding = ContentEncoding.Base64,
                                    FileName = Path.GetFileName(path)
                                };
                                multipart.Add(attimg);
                            }
                        }
                        catch (FileNotFoundException ex)
                        {
                            //找不到文件就不提交附件了
                        }
                    }
                }
                //赋值邮件内容
                message.Body = multipart;
                //开始发送
                using (var client = new SmtpClient())
                {
                    client.Connect(this._STEPNAME, this._STEPPORT, false);
                    client.Authenticate(this._USEREMAIL, this._PASSWORD);
                    client.Send(message);
                    client.Disconnect(true);
                }
               // return "邮件发送成功";
            }
            catch (Exception ex)
            {
               // return "邮箱发送失败";
            }
        }
    }
 
    /// <summary>
    /// 测试调用方法
    /// </summary>
    public class Test{
        private email=new EmailHelper("发送的邮箱","Smtp授权码");
        public void SendEmail()
        {
            email.SendEmail("对方的邮箱", "对方邮箱名称也可以是邮箱","标题", "内容", "<b>这是html标记的文本</b>", "附加地址")
        }
    }
}

附件问题处理

List<FileStream> list = new List<FileStream>(attachments.Count());
        foreach (var path in attachments)
        {
            if (!File.Exists(path))
            {
                throw new FileNotFoundException("文件未找到", path);
            }
            var fileName = Path.GetFileName(path);
            var fileType = MimeTypes.GetMimeType(path);
            var contentTypeArr = fileType.Split('/');
            var contentType = new ContentType(contentTypeArr[0], contentTypeArr[1]);
            MimePart attachment = null;
            var fs = new FileStream(path, FileMode.Open);
            list.Add(fs);
            attachment = new MimePart(contentType)
            {
                Content = new MimeContent(fs),
                ContentDisposition = new ContentDisposition(ContentDisposition.Attachment),
                ContentTransferEncoding = ContentEncoding.Base64,

            };

            var charset = "GB18030";
            attachment.ContentType.Parameters.Add(charset, "name", fileName);
            attachment.ContentDisposition.Parameters.Add(charset, "filename", fileName);

            foreach (var param in attachment.ContentDisposition.Parameters)
                param.EncodingMethod = ParameterEncodingMethod.Rfc2047;
            foreach (var param in attachment.ContentType.Parameters)
                param.EncodingMethod = ParameterEncodingMethod.Rfc2047;
            collection.Add(attachment);
        }
        await SendEmail(body, subject, isHtml, to, cc, collection);


        foreach (var fs in list)
        {
            fs.Dispose();//手动释放
        }

解决文件名不能使用中文

原因是字符编码的问题

MimePart attachment = null;
var fs = new FileStream(path, FileMode.Open);
list.Add(fs);
attachment = new MimePart(contentType)
{
    Content = new MimeContent(fs),
    ContentDisposition = new ContentDisposition(ContentDisposition.Attachment),
    ContentTransferEncoding = ContentEncoding.Base64,

};

var charset = "GB18030";
attachment.ContentType.Parameters.Add(charset, "name", fileName);
attachment.ContentDisposition.Parameters.Add(charset, "filename", fileName);

解决附件名字中文乱码主要依靠最后三行代码，将name和filename的字符集指定为GB18030即可。

解决文件名不能超过41字符

var attachment = bodyBuilder.Attachments.Add (.....);
foreach (var param in attachment.ContentDisposition.Parameters)
    param.EncodingMethod = ParameterEncodingMethod.Rfc2047;
foreach (var param in attachment.ContentType.Parameters)
    param.EncodingMethod = ParameterEncodingMethod.Rfc2047;

别忘了释放文件流

记录2

string mailAccount = "abc@126.com";
            string mainPassword = "ABVCDEFGDSDF";
            var client = new MailKit.Net.Smtp.SmtpClient();
            client.Connect("smtp.126.com", 25, SecureSocketOptions.None);
            client.AuthenticationMechanisms.Remove("XOAUTH2");
            client.Authenticate(mailAccount, mainPassword);

            var message = new MimeMessage();
            message.From.Add(new MailboxAddress("testNameFrom", "abc@126.com"));
            message.To.Add(new MailboxAddress("testNameTo", "abcd@163.com"));
            message.Subject = "测试发送邮件的标题";

            var html = new TextPart("html")
            {
                Text = @"p您好，张三：br
                        p附件里是详细内容，请查收！br
                        p-- 管家王小明br"
            };

            var alternative = new Multipart("alternative");
            alternative.Add(html);

            string pngPath = @"C:UserswjxDesktoplogo.png";
            var attachmentPng = new MimePart("image", "png")
            {
                Content = new MimeContent(File.OpenRead(pngPath), ContentEncoding.Default),
                ContentDisposition = new ContentDisposition(ContentDisposition.Attachment),
                ContentTransferEncoding = ContentEncoding.Base64,
                FileName = Path.GetFileName(pngPath)
            };

            string zipPath = @"C:UserswjxDesktop中国百度的logo.zip";
            var attachmentZip = new MimePart("application", "zip")
            {
                Content = new MimeContent(File.OpenRead(zipPath), ContentEncoding.Default),
                ContentDisposition = new ContentDisposition(ContentDisposition.Attachment),
                ContentTransferEncoding = ContentEncoding.Base64,
                FileName = Path.GetFileName(zipPath)
            };

            var multipart = new Multipart("mixed");
            multipart.Add(alternative);

            multipart.Add(attachmentPng);
            multipart.Add(attachmentZip);

            message.Body = multipart;

            client.Send(message);
            client.Disconnect(true);