I'm used "for" operator.
try
{
string s = textBox2.Text;
string[] f = s.Split(',');
for (int i = 0; i < f.Length; i++)
{
MailMessage message = new MailMessage(); // Create instance of message
message.To.Add(f[i]); // Add receiver
message.From = new System.Net.Mail.MailAddress(c);// Set sender .In this case the same as the username
message.Subject = label3.Text; // Set subject
message.Body = richTextBox1.Text; // Set body of message
client.Send(message); // Send the message
message = null; // Clean up
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}