我不明白为什么这个代码不能工作。我得到一个错误,说属性不能被分配

MailMessage mail = new MailMessage();
SmtpClient client = new SmtpClient();
client.Port = 25;
client.DeliveryMethod = SmtpDeliveryMethod.Network;
client.UseDefaultCredentials = false;
client.Host = "smtp.gmail.com";
mail.To = "user@hotmail.com"; // <-- this one
mail.From = "you@yourcompany.example";
mail.Subject = "this is a test email.";
mail.Body = "this is my test email body";
client.Send(mail);

当前回答

这个答案的特点是:

尽可能使用“Using”(IDisposable接口) 使用对象初始化器 异步编程 将SmtpConfig提取到外部类(根据需要进行调整)

下面是提取的代码:

    public async Task SendAsync(string subject, string body, string to)
    {
        using (var message = new MailMessage(smtpConfig.FromAddress, to)
        {
            Subject = subject,
            Body = body,
            IsBodyHtml = true
        })
        {
            using (var client = new SmtpClient()
            {
                Port = smtpConfig.Port,
                DeliveryMethod = SmtpDeliveryMethod.Network,
                UseDefaultCredentials = false,
                Host = smtpConfig.Host,
                Credentials = new NetworkCredential(smtpConfig.User, smtpConfig.Password),
            })
            {
                await client.SendMailAsync(message);
            }
        }                                     
    }

Class SmtpConfig:

public class SmtpConfig
{
    public string Host { get; set; }
    public string User { get; set; }
    public string Password { get; set; }
    public int Port { get; set; }
    public string FromAddress { get; set; }
}

其他回答

如果你想让你的电子邮件和密码不出现在你的代码,并希望你的公司电子邮件客户端服务器使用你的windows凭据使用下面。

client.Credentials = CredentialCache.DefaultNetworkCredentials;

MailKit是一个开源的跨平台。net邮件客户端库,它基于MimeKit并针对移动设备进行了优化。 它拥有比System.Net.Mail更好的更多高级功能 微软通过MimeKit支持TNEF。

从这里下载nuget包。

请看这个例子,你可以发送邮件

            MimeMessage mailMessage = new MimeMessage();
            mailMessage.From.Add(new MailboxAddress(senderName, sender@address.com));
            mailMessage.Sender = new MailboxAddress(senderName, sender@address.com);
            mailMessage.To.Add(new MailboxAddress(emailid, emailid));
            mailMessage.Subject = subject;
            mailMessage.ReplyTo.Add(new MailboxAddress(replyToAddress));
            mailMessage.Subject = subject;
            var builder = new BodyBuilder();
            builder.TextBody = "Hello There";            
            try
            {
                using (var smtpClient = new SmtpClient())
                {
                    smtpClient.Connect("HostName", "Port", MailKit.Security.SecureSocketOptions.None);
                    smtpClient.Authenticate("user@name.com", "password");

                    smtpClient.Send(mailMessage);
                    Console.WriteLine("Success");
                }
            }
            catch (SmtpCommandException ex)
            {
                Console.WriteLine(ex.ToString());              
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());                
            }

这样的:

mail.To = "user@hotmail.com";

应该是:

mail.To.Add(new MailAddress("user@hotmail.com"));

使用发件人和收件人的电子邮件地址初始化MailMessage。应该是这样的

string from = "codeforwin@gmail.com";  //Senders email   
string to = "reciever@gmail.com";  //Receiver's email  
MailMessage msg = new MailMessage(from, to); 

阅读如何用c#发送电子邮件的完整代码片段

public static void SendMail(MailMessage Message)
{
    SmtpClient client = new SmtpClient();
    client.Host = "smtp.googlemail.com";
    client.Port = 587;
    client.UseDefaultCredentials = false;
    client.DeliveryMethod = SmtpDeliveryMethod.Network;
    client.EnableSsl = true;
    client.Credentials = new NetworkCredential("myemail@gmail.com", "password");
    client.Send(Message); 
}