smtpClient发邮件错误:不允许使用邮箱名称

   许多网站个人密码丢失，找回密码的办法是：系统自动发送给你以前的密码到你的密保邮箱。以下是自动发送密码的核心代码：注意看加颜色的代码行。

 

   给本方法带参数如:EmailSend("这个参数是邮件的内容-body","收件人[e-mail]","发件人[e-mail]","发件人密码-1243")

 

    /// <summary>
    /// 发送邮件
    /// </summary>
    /// <param name="mailinfo">邮件的一些属性</param>
    /// <param name="smtpname">SMTP事务的主机名称</param>
    /// <param name="username">自己的邮箱登录名</param>
    /// <param name="pwd">邮箱的密码</param>
    /// <returns></returns>
    /// <author>Wilhelm Von Arminius</author>
    public Boolean EmailSend(MailMessage mailinfo, string username, string adminusername, string adminpwd)
    {
        bool flag = false;
        try
        {
            MailAddress from = new MailAddress(adminusername); //邮件的发件人
            MailMessage mail = new MailMessage();
            //设置邮件的标题
            mail.Subject = "淘宝会员密码";  
            //设置邮件的发件人
            mail.From = from;
            //设置邮件的收件人
            string address = username;
            string displayName = username.Split('@').FirstOrDefault().ToString();
            mail.To.Add(new MailAddress(address, displayName, System.Text.Encoding.UTF8));

            /**/
            //设置邮件的内容
            mail.Body = mailinfo.Body;
            //设置邮件的格式
            mail.BodyEncoding = System.Text.Encoding.UTF8;
            mail.IsBodyHtml = true;

            //设置邮件的发送级别
            mail.Priority = MailPriority.Normal;
            mail.DeliveryNotificationOptions = DeliveryNotificationOptions.OnSuccess;

            SmtpClient client = new SmtpClient();
            //设置用于 SMTP 事务的主机的名称，填IP地址也可以了            
            client = new System.Net.Mail.SmtpClient("smtp.ym.163.com");//其它的，列如：smtp.qq.com,smtp.sina.com

            //设置用于 SMTP 事务的端口，默认的是 25
            client.Port = 25;
            client.UseDefaultCredentials = true;            
            string ss = adminusername.Split('@').FirstOrDefault().ToString();
            // client.Credentials = new System.Net.NetworkCredential(ss, adminpwd); //这一行代码会报错，不能去掉@之后语句.
            client.Credentials = new System.Net.NetworkCredential(adminusername, adminpwd); //("[e-mail]","111")
            client.DeliveryMethod = SmtpDeliveryMethod.Network;
            client.Timeout = 300000;           
            client.Send(mail);
            flag = true;
        }
        catch (Exception ex)
        {
            ex.Message.ToString();
        }
        return flag;
    }