net send command program debugging in C# - c#-4.0

Question

I write a program to execute and send msg using windows net send command.Its working fine for single receptor.But the problem happen when i want to send message in many receptors. i use a for loop to take receptor name from a list box. Here all message go to the first receptor.The problem happen on process execution.So far i guess the process is not clear or dead on the time.
Can any body guide me how i can send the msg to multiple users at a time?
my code below:
string sendingMessage = messageRichTextBox.Text;
string[] recepentAddressArray = new string[recepentAddressListBox.Items.Count];
for (int j = 0; j < recepentAddressListBox.Items.Count; j++) // Getting address from list box
{
recepentAddressArray[j] = recepentAddressListBox.Items[j].ToString();
string recepantAddress = recepentAddressArray[j];
try
{
string strLine = "net send " + recepantAddress + " " + sendingMessage + " >C:netsend.log";
FileStream fs = new FileStream("c:netsend.bat", FileMode.Create, FileAccess.Write);
StreamWriter streamWriter = new StreamWriter(fs);
streamWriter.BaseStream.Seek(0, SeekOrigin.End);
streamWriter.Write(strLine);
streamWriter.Flush();
streamWriter.Close();
fs.Close();
Process p = new Process();
p.StartInfo.FileName = "C:netsend.bat";
p.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
p.Start();
p.WaitForExit();
p.Close();
FileStream fsOutput = new FileStream("C:netsend.log", FileMode.Open, FileAccess.Read);
StreamReader reader = new StreamReader(fsOutput);
reader.BaseStream.Seek(0, SeekOrigin.Begin);
string strOut = reader.ReadLine();
reader.Close();
fsOutput.Close();
}
catch (Exception)
{
MessageBox.Show("ERROR");
}
}