用POP3取邮件时，使用正确的密码，但检测结果返回-ERR

Question

server:pop.163.com 或者pop3.163.com 
port:110
user:pop3mail
pass:123456我的代码如下：
TcpClient tcpclient = new TcpClient("pop.163.com",110);
Byte[] outbytes;
string input = "";
NetworkStream ns = null;
ns = tcpclient.GetStream();
outbytes = new byte[tcpclient.ReceiveBufferSize];
ns.Read(outbytes, 0, (int)tcpclient.ReceiveBufferSize);
label1.Text = Encoding.ASCII.GetString(outbytes);input = "USER" + "pop3mail" + "\r\n";
outbytes = Encoding.ASCII.GetBytes(input.ToCharArray());
ns.Write(outbytes, 0,outbytes.Length );
outbytes = new byte[tcpclient.ReceiveBufferSize];
ns.Read(outbytes, 0, (int)tcpclient.ReceiveBufferSize);
label1.Text += "  " + Encoding.ASCII.GetString(outbytes);input = "pass" + "123456" + "\r\n";
outbytes = Encoding.ASCII.GetBytes(input.ToCharArray());
ns.Write(outbytes, 0, outbytes.Length );
outbytes = new byte[tcpclient.ReceiveBufferSize];
ns.Read(outbytes, 0, (int)tcpclient.ReceiveBufferSize);
label1.Text += "  " + Encoding.ASCII.GetString(outbytes);input = "QUIT" + "\r\n";
outbytes = Encoding.ASCII.GetBytes(input.ToCharArray());
ns.Write(outbytes, 0, outbytes.Length );
outbytes = new byte[tcpclient.ReceiveBufferSize];
ns.Read(outbytes, 0, (int)tcpclient.ReceiveBufferSize);
label1.Text += "  " + Encoding.ASCII.GetString(outbytes);tcpclient.Close();

Answer 1

是不是缺少空格
input = "USER" + "pop3mail" + "\r\n";
应该是　input = "USER　" + "pop3mail" + "\r\n";

Answer 2

input = "USER" + "pop3mail" + "\r\n";
这部分的返回信息是正确的
可是到了密码的时候才有问题的

Answer 3

我又试了一下， sandsboy(沙滩男孩) 你说的对，是这样的，问题解决了。谢谢！