Why do I get "'property cannot be assigned" when sending an SMTP email?

I can't understand why this code is not working. I get an error saying property can not be assigned

MailMessage mail = new MailMessage();
SmtpClient client = new SmtpClient();            
client.Port = 25;
client.DeliveryMethod = SmtpDeliveryMethod.Network;
client.UseDefaultCredentials = false;
client.Host = "smtp.gmail.com";
mail.To = "[email protected]"; // <-- this one
mail.From = "[email protected]";
mail.Subject = "this is a test email.";
mail.Body = "this is my test email body";
client.Send(mail);

mail.To and mail.From are readonly. Move them to the constructor.

using System.Net.Mail;

...

MailMessage mail = new MailMessage("[email protected]", "[email protected]");
SmtpClient client = new SmtpClient();
client.Port = 25;
client.DeliveryMethod = SmtpDeliveryMethod.Network;
client.UseDefaultCredentials = false;
client.Host = "smtp.gmail.com";
mail.Subject = "this is a test email.";
mail.Body = "this is my test email body";
client.Send(mail);

This :

mail.To = "[email protected]";

Should be:

mail.To.Add(new MailAddress("[email protected]"));

Finally got working :)

using System.Net.Mail;
using System.Text;

...

// Command line argument must the the SMTP host.
SmtpClient client = new SmtpClient();
client.Port = 587;
client.Host = "smtp.gmail.com";
client.EnableSsl = true;
client.Timeout = 10000;
client.DeliveryMethod = SmtpDeliveryMethod.Network;
client.UseDefaultCredentials = false;
client.Credentials = new System.Net.NetworkCredential("[email protected]","password");

MailMessage mm = new MailMessage("[email protected]", "[email protected]", "test", "test");
mm.BodyEncoding = UTF8Encoding.UTF8;
mm.DeliveryNotificationOptions = DeliveryNotificationOptions.OnFailure;

client.Send(mm);

sorry about poor spelling before

public static void SendMail(MailMessage Message)
{
    SmtpClient client = new SmtpClient();
    client.Host = "smtp.googlemail.com";
    client.Port = 587;
    client.UseDefaultCredentials = false;
    client.DeliveryMethod = SmtpDeliveryMethod.Network;
    client.EnableSsl = true;
    client.Credentials = new NetworkCredential("[email protected]", "password");
    client.Send(Message); 
}

This is how it works for me. Hope you find it useful

MailMessage objeto_mail = new MailMessage();
SmtpClient client = new SmtpClient();
client.Port = 25;
client.Host = "smtp.internal.mycompany.com";
client.Timeout = 10000;
client.DeliveryMethod = SmtpDeliveryMethod.Network;
client.UseDefaultCredentials = false;
client.Credentials = new System.Net.NetworkCredential("user", "Password");
objeto_mail.From = new MailAddress("[email protected]");
objeto_mail.To.Add(new MailAddress("[email protected]"));
objeto_mail.Subject = "Password Recover";
objeto_mail.Body = "Message";
client.Send(objeto_mail);