这样发送电子邮件有什么错误？

[rushing]

public static void SendMail(string receiver,string subject,string content)
{
MailAddress from = new MailAddress("[e-mail]", "aa", System.Text.Encoding.UTF8);
MailAddress to = new MailAddress(receiver);

MailMessage mm = new MailMessage(from, to);
mm.Subject = subject;
mm.SubjectEncoding = System.Text.Encoding.UTF8;
mm.Body = content;
mm.BodyEncoding = System.Text.Encoding.UTF8;


SmtpClient client = new SmtpClient("xxxx");
client.Credentials = new NetworkCredential("aa", "xxxx");
client.Send(mm);
}

错误现象为：
Exception Details: System.Net.Sockets.SocketException: 您的主机中的软件放弃了一个已建立的连接。

[活靶子哥哥]

你的杀毒软件or防火墙将连接断开了

[rushing]

关闭了天网防火墙，也不行。

[活靶子哥哥]

see:
http://blog.joycode.com/ghj/archive/2006/03/16/72945.aspx