背景

利用代码发送邮件在工作中还是比较常见的，相信大家都用过SmtpClient来处理发送邮件的操作，不过这个类以及被标记已过时，所以介绍一个微软推荐的库MailKit来处理。

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

需要邮件功能

1、服务提供方:需提供邮件收发客户端或Web服务。如:QQ邮箱、GMail邮箱、126、163等知名邮件服务提供商。注:如果你使用的第三方不知名邮件服务商提供的邮件收发服务,通过其发出的邮件,可能会被其他知名邮件服务提供商的STMP服务器视为是"恶意邮件或垃圾邮件"!

2、消息推送:消息推送方

3、App:某些网站会员的注册功能或者功能激活功能。

协议

1、SMTP(Simple Mail Transfer Protocol)   ---简单邮件传输协议

2、POP3(Post Office Protocol -Version3)   ---邮局协议第三个版本

代码实现

1、新建项目 引用 MailKit

using MailKit.Net.Smtp;using MimeKit;

2、指定发件人、收件人、附件等信息

[HttpPost][Route("sendmail")]public bool Sendmail(SendmailDto model){string mailTo = model.mail;string title = model.title;string requestId = Guid.NewGuid().ToString("N");string path = WriteFilepath(requestId, title + ".html", model.str);string docpath = path.Replace(".html", ".docx");try{string applicationRoot = AppContext.BaseDirectory;var provider = new PhysicalFileProvider(applicationRoot);string apath = @"C:/www/fengnan";// string apath = @"C:/net6.0";var filePath =//applicationRoot +apath + $"/Template/fldoc/" + requestId + "/";var filePath2 =//applicationRoot +apath + $"/Template/fldoc/" + requestId + "/"+ title + ".html";ecmd("soffice --headless --convert-to docx:\"Office Open XML Text\" " + filePath2 + " --outdir " + filePath);//   string docpath = path.Replace(".html", ".docx");}catch (Exception ex){_logger.Error(ex);}// string mailFrom = "xxxx@qq.com";string mailFrom = "xxx@xx.net";//   mailTo = "xx@xxx.com";string Text = "内容见附件，请查收<br/> 感谢";string mailFromAccount = "xxx@qq.com";string mailPassword = "xxxx";string mailFromAccount = "xxx@xx.net";string mailPassword = "xxxx@";var contentRoot = Directory.GetCurrentDirectory();var webRoot = Path.Combine(contentRoot, "wwwroot");///  string path = Path.Combine(webRoot, "Images/icc.png");//  string path = @"D:\xxxx知.html";//  string Text = @"Hey Chandler,//I just wanted to let you know that Monica and I were going to go play some paintball, you in?//-- Joey";Config eConfig = new Config{                From = new MailAddress("xxxx", mailFrom),//  Host = "smtp.qq.com",                Host = "smtp.exmail.qq.com",                MailFromAccount = mailFromAccount,                MailPassword = mailPassword,// Port = 587,                Port = 465,                UseSsl = true,                IsHtml = true};List<MailAddress> tos = new List<MailAddress>();tos.Add(new MailAddress("", mailTo));List<string> flist = new List<string>();if (System.IO.File.Exists(docpath)){flist.Add(docpath);//docpath}else{flist.Add(path);}Mailhelper.SendEmail(eConfig, tos, title, Text, flist.ToArray());return true;}

3、发邮件帮助类

using MimeKit;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Threading.Tasks;
namespace DFTech.Service.Filters
{/// <summary>/// 发邮件/// </summary>public class Mailhelper{/// <summary>/// 发邮件/// </summary>/// <param name="config"></param>/// <param name="tos"></param>/// <param name="subject"></param>/// <param name="message"></param>/// <param name="attachments"></param>/// <returns></returns>public  static void SendEmail(Config config, List<MailAddress> tos, string subject, string message, params string[] attachments){var emailMessage = new MimeMessage();emailMessage.From.Add((MailboxAddress)config.From);foreach (var to in tos)emailMessage.To.Add(to as MailAddress);emailMessage.Subject = subject;var alternative = new Multipart("alternative");if (config.IsHtml)alternative.Add(new TextPart("html") { Text = message });elsealternative.Add(new TextPart("plain") { Text = message });if (attachments != null){foreach (string f in attachments){var attachment = new MimePart()//("image", "png"){ContentObject = new ContentObject(File.OpenRead(f), ContentEncoding.Default),ContentDisposition = new ContentDisposition(ContentDisposition.Attachment),ContentTransferEncoding = ContentEncoding.Base64,FileName = Path.GetFileName(f)};alternative.Add(attachment);}}emailMessage.Body = alternative;using (var client = new SmtpClient()){client.Connect(config.Host, config.Port, config.UseSsl);// SecureSocketOptions.Noneclient.AuthenticationMechanisms.Remove("XOAUTH2");client.Authenticate(config.MailFromAccount, config.MailPassword);client.Send(emailMessage);client.Disconnect(true);}}}public class Config{public int Port { get; set; } = 25; //25public string Host { get; set; } //smtp.hantianwei.cnpublic bool IsHtml { get; set; } = true;public bool UseSsl { get; set; } = false;public string MailFromAccount { get; set; }//mail@hantianwei.cnpublic string MailPassword { get; set; }public MailAddress From { get; set; }}/// <summary>////// </summary>public class MailAddress : MailboxAddress{public MailAddress(string name, string address) : base(name, address){}public MailAddress(Encoding encoding, string name, string address) : base(encoding, name, address){}}
}