как отправить несколько адресов электронной почты [дубликат]

namespace WebForms.Code.Logging {

    public class ObserverLogToEmail: ILog {
        private string from;
        private string to;
        private string subject;
        private string body;
        private SmtpClient smtpClient;
        private MailMessage mailMessage;
        private MailPriority mailPriority;
        private MailAddressCollection mailAddressCollection;
        private MailAddress fromMailAddress, toMailAddress;
        public MailAddressCollection toMailAddressCollection {
            get;
            set;
        }
        public MailAddressCollection ccMailAddressCollection {
            get;
            set;
        }
        public MailAddressCollection bccMailAddressCollection {
            get;
            set;
        }

        public ObserverLogToEmail(string from, string to, string subject, string body, SmtpClient smtpClient) {
            this.from = from;
            this.to = to;
            this.subject = subject;
            this.body = body;

            this.smtpClient = smtpClient;
        }

        public ObserverLogToEmail(MailAddress fromMailAddress, MailAddress toMailAddress,
        string subject, string content, SmtpClient smtpClient) {
            try {
                this.fromMailAddress = fromMailAddress;
                this.toMailAddress = toMailAddress;
                this.subject = subject;
                this.body = content;

                this.smtpClient = smtpClient;

                mailAddressCollection = new MailAddressCollection();

            } catch {
                throw new SmtpException(SmtpStatusCode.CommandNotImplemented);
            }
        }

        public ObserverLogToEmail(MailAddressCollection fromMailAddressCollection,
        MailAddressCollection toMailAddressCollection,
        string subject, string content, SmtpClient smtpClient) {
            try {
                this.toMailAddressCollection = toMailAddressCollection;
                this.ccMailAddressCollection = ccMailAddressCollection;
                this.subject = subject;
                this.body = content;

                this.smtpClient = smtpClient;

            } catch {
                throw new SmtpException(SmtpStatusCode.CommandNotImplemented);
            }
        }

        public ObserverLogToEmail(MailAddressCollection toMailAddressCollection,
        MailAddressCollection ccMailAddressCollection,
        MailAddressCollection bccMailAddressCollection,
        string subject, string content, SmtpClient smtpClient) {
            try {
                this.toMailAddressCollection = toMailAddressCollection;
                this.ccMailAddressCollection = ccMailAddressCollection;
                this.bccMailAddressCollection = bccMailAddressCollection;

                this.subject = subject;
                this.body = content;

                this.smtpClient = smtpClient;

            } catch {
                throw new SmtpException(SmtpStatusCode.CommandNotImplemented);
            }
        }#region ILog Members

        // sends a log request via email.
        // actual email 'Send' calls are commented out.
        // uncomment if you have the proper email privileges.
        public void Log(object sender, LogEventArgs e) {
            string message = "[" + e.Date.ToString() + "] " + e.SeverityString + ": " + e.Message;
            fromMailAddress = new MailAddress("", "HaNN", System.Text.Encoding.UTF8);
            toMailAddress = new MailAddress("", "XXX", System.Text.Encoding.UTF8);

            mailMessage = new MailMessage(fromMailAddress, toMailAddress);
            mailMessage.Subject = subject;
            mailMessage.Body = body;

            // commented out for now. you need privileges to send email.
            // _smtpClient.Send(from, to, subject, body);
            smtpClient.Send(mailMessage);
        }

        public void LogAllEmails(object sender, LogEventArgs e) {
            try {
                string message = "[" + e.Date.ToString() + "] " + e.SeverityString + ": " + e.Message;

                mailMessage = new MailMessage();
                mailMessage.Subject = subject;
                mailMessage.Body = body;

                foreach(MailAddress toMailAddress in toMailAddressCollection) {
                    mailMessage.To.Add(toMailAddress);

                }
                foreach(MailAddress ccMailAddress in ccMailAddressCollection) {
                    mailMessage.CC.Add(ccMailAddress);
                }
                foreach(MailAddress bccMailAddress in bccMailAddressCollection) {
                    mailMessage.Bcc.Add(bccMailAddress);
                }
                if (smtpClient == null) {
                    var smtp = new SmtpClient {
                        Host = "smtp.gmail.com",
                        Port = 587,
                        EnableSsl = true,
                        DeliveryMethod = SmtpDeliveryMethod.Network,
                        Credentials = new NetworkCredential("yourEmailAddress", "yourPassword"),
                        Timeout = 30000
                    };
                } else smtpClient.SendAsync(mailMessage, null);
            } catch (Exception) {

                throw;
            }
        }
    }

Мой код для решения этой проблемы:

private void sendMail()
{   
    //This list can be a parameter of metothd
    List<MailAddress> lst = new List<MailAddress>();

    lst.Add(new MailAddress("mouse@xxxx.com"));
    lst.Add(new MailAddress("duck@xxxx.com"));
    lst.Add(new MailAddress("goose@xxxx.com"));
    lst.Add(new MailAddress("wolf@xxxx.com"));


    try
    {


        MailMessage objeto_mail = new MailMessage();
        SmtpClient client = new SmtpClient();
        client.Port = 25;
        client.Host = "10.15.130.28"; //or SMTP name
        client.Timeout = 10000;
        client.DeliveryMethod = SmtpDeliveryMethod.Network;
        client.UseDefaultCredentials = false;
        client.Credentials = new System.Net.NetworkCredential("from@email.com", "password");
        objeto_mail.From = new MailAddress("from@email.com");

        //add each email adress
        foreach (MailAddress m in lst)
        {
            objeto_mail.To.Add(m);
        }


        objeto_mail.Subject = "Sending mail test";
        objeto_mail.Body = "Functional test for automatic mail :-)";
        client.Send(objeto_mail);


    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
}

Предложение StewieFG действительно, но если вы хотите добавить имя получателя, используйте это, с тем, что Марко разместил выше, но сначала адрес электронной почты и второе имя:

msg.To.Add(new MailAddress("your@email1.com","Your name 1"));
msg.To.Add(new MailAddress("your@email2.com","Your name 2"));

 string[] MultiEmails = email.Split(',');
 foreach (string ToEmail in MultiEmails)
 {
    message.To.Add(new MailAddress(ToEmail)); //adding multiple email addresses
 }

Я использую оператор «для».

try
{
    string s = textBox2.Text;
    string[] f = s.Split(',');

    for (int i = 0; i < f.Length; i++)
    {
        MailMessage message = new MailMessage(); // Create instance of message
        message.To.Add(f[i]); // Add receiver
        message.From = new System.Net.Mail.MailAddress(c);// Set sender .In this case the same as the username
        message.Subject = label3.Text; // Set subject
        message.Body = richTextBox1.Text; // Set body of message
        client.Send(message); // Send the message
        message = null; // Clean up
    }

}

catch (Exception ex)
{

    MessageBox.Show(ex.Message);
}

MailAddress fromAddress = new MailAddress  (fromMail,fromName);
MailAddress toAddress = new MailAddress(toMail,toName);
MailMessage message = new MailMessage(fromAddress,toAddress);
message.Subject = subject;
message.Body = body;
SmtpClient smtp = new SmtpClient()
{
    Host = host, Port = port,
    enabHost = "smtp.gmail.com",
    Port = 25,
    EnableSsl = true,
    UseDefaultCredentials = true,
    Credentials = new  NetworkCredentials (fromMail, password)
};
smtp.send(message);