包括这个,

using System.Net.Mail;

然后,

MailMessage sendmsg = new MailMessage(SendersAddress, ReceiversAddress, subject, body); 
SmtpClient client = new SmtpClient("smtp.gmail.com");

client.Port = 587;
client.Credentials = new System.Net.NetworkCredential("mail-id@gmail.com","password");
client.EnableSsl = true;

client.Send(sendmsg);

谷歌已经从我们的谷歌帐户中删除了不太安全的应用程序设置，这意味着我们不能再使用我们实际的谷歌密码从SMTP服务器发送电子邮件。我们需要使用Xoauth2并授权用户，或者在启用了2fa的帐户上创建一个应用程序密码。

一旦创建了应用程序密码，就可以用来代替你的标准gmail密码。

class Program
{
    private const string To = "test@test.com";
    private const string From = "test@test.com";
    
    private const string GoogleAppPassword = "XXXXXXXX";
    
    private const string Subject = "Test email";
    private const string Body = "<h1>Hello</h1>";
    
    
    static void Main(string[] args)
    {
        Console.WriteLine("Hello World!");
        
        var smtpClient = new SmtpClient("smtp.gmail.com")
        {
            Port = 587,
            Credentials = new NetworkCredential(From , GoogleAppPassword),
            EnableSsl = true,
        };
        var mailMessage = new MailMessage
        {
            From = new MailAddress(From),
            Subject = Subject,
            Body = Body,
            IsBodyHtml = true,
        };
        mailMessage.To.Add(To);

        smtpClient.Send(mailMessage);
    }
}

快速修复SMTP用户名和密码不接受错误

来源:在ASP发送电子邮件。净c#

下面是一个使用c#发送邮件的示例工作代码，在下面的例子中，我使用谷歌的smtp服务器。

代码是相当不言自明的，替换电子邮件和密码与您的电子邮件和密码值。

public void SendEmail(string address, string subject, string message)
{
    string email = "yrshaikh.mail@gmail.com";
    string password = "put-your-GMAIL-password-here";

    var loginInfo = new NetworkCredential(email, password);
    var msg = new MailMessage();
    var smtpClient = new SmtpClient("smtp.gmail.com", 587);

    msg.From = new MailAddress(email);
    msg.To.Add(new MailAddress(address));
    msg.Subject = subject;
    msg.Body = message;
    msg.IsBodyHtml = true;

    smtpClient.EnableSsl = true;
    smtpClient.UseDefaultCredentials = false;
    smtpClient.Credentials = loginInfo;
    smtpClient.Send(msg);
}

试试这个

public static bool Send(string receiverEmail, string ReceiverName, string subject, string body)
{
        MailMessage mailMessage = new MailMessage();
        MailAddress mailAddress = new MailAddress("abc@gmail.com", "Sender Name"); // abc@gmail.com = input Sender Email Address 
        mailMessage.From = mailAddress;
        mailAddress = new MailAddress(receiverEmail, ReceiverName);
        mailMessage.To.Add(mailAddress);
        mailMessage.Subject = subject;
        mailMessage.Body = body;
        mailMessage.IsBodyHtml = true;

        SmtpClient mailSender = new SmtpClient("smtp.gmail.com", 587)
        {
            EnableSsl = true,
            UseDefaultCredentials = false,
            DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network,
            Credentials = new NetworkCredential("abc@gmail.com", "pass")   // abc@gmail.com = input sender email address  
                                                                           //pass = sender email password
        };

        try
        {
            mailSender.Send(mailMessage);
            return true;
        }
        catch (SmtpFailedRecipientException ex)
        { 
          // Write the exception to a Log file.
        }
        catch (SmtpException ex)
        { 
           // Write the exception to a Log file.
        }
        finally
        {
            mailSender = null;
            mailMessage.Dispose();
        }
        return false;
}

using System;
using System.Net;
using System.Net.Mail;

namespace SendMailViaGmail
{
   class Program
   {
   static void Main(string[] args)
   {

      //Specify senders gmail address
      string SendersAddress = "Sendersaddress@gmail.com";
      //Specify The Address You want to sent Email To(can be any valid email address)
      string ReceiversAddress = "ReceiversAddress@yahoo.com";
      //Specify The password of gmial account u are using to sent mail(pw of sender@gmail.com)
      const string SendersPassword = "Password";
      //Write the subject of ur mail
      const string subject = "Testing";
      //Write the contents of your mail
      const string body = "Hi This Is my Mail From Gmail";

      try
      {
        //we will use Smtp client which allows us to send email using SMTP Protocol
        //i have specified the properties of SmtpClient smtp within{}
        //gmails smtp server name is smtp.gmail.com and port number is 587
        SmtpClient smtp = new SmtpClient
        {
           Host = "smtp.gmail.com",
           Port = 587,
           EnableSsl = true,
           DeliveryMethod = SmtpDeliveryMethod.Network,
           Credentials = new NetworkCredential(SendersAddress, SendersPassword),
           Timeout = 3000
        };

        //MailMessage represents a mail message
        //it is 4 parameters(From,TO,subject,body)

        MailMessage message = new MailMessage(SendersAddress, ReceiversAddress, subject, body);
        /*WE use smtp sever we specified above to send the message(MailMessage message)*/

        smtp.Send(message);
        Console.WriteLine("Message Sent Successfully");
        Console.ReadKey();
     }
     catch (Exception ex)
     {
        Console.WriteLine(ex.Message);
        Console.ReadKey();
     }
}
}
}

试试这个,

    private void button1_Click(object sender, EventArgs e)
    {
        try
        {
            MailMessage mail = new MailMessage();
            SmtpClient SmtpServer = new SmtpClient("smtp.gmail.com");

            mail.From = new MailAddress("your_email_address@gmail.com");
            mail.To.Add("to_address");
            mail.Subject = "Test Mail";
            mail.Body = "This is for testing SMTP mail from GMAIL";

            SmtpServer.Port = 587;
            SmtpServer.Credentials = new System.Net.NetworkCredential("username", "password");
            SmtpServer.EnableSsl = true;

            SmtpServer.Send(mail);
            MessageBox.Show("mail Send");
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.ToString());
        }
    }