首先设置自己的邮箱  设置   账号

吧这些全部选中就可以了

POP3/IMAP/SMTP/Exchange/CardDAV/CalDAV服务

 

public static void Sender()        {            try            {                SmtpClient client = new SmtpClient();                client.Host = "smtp.qq.com";                MailMessage mm = new MailMessage();                client.Port = 25;                mm.From = new MailAddress("873113580@qq.com");                mm.To.Add(new MailAddress("625903917@qq.com"));                mm.Subject = "Hello~!";                mm.Body = "hahahahaa ";                mm.IsBodyHtml = false;                mm.Priority = MailPriority.High;                client.Credentials = new NetworkCredential("873113580@qq.com", "*******");                client.Send(mm);            }            catch (Exception ex)            {                Console.WriteLine(ex.Message);            }        }