Send Large Amounts Of Email Via C# Web Page?

I have part of a project whereby I need to send 1 to up to 2000 emails from a webpage. One open source bug tracker used a Thread to send emails but it was riddled with bugs. So just want to know if anyone has any ideas of how I can create a procedure that send up to 2000 emails a go?

I was told by one of my colleagues to leave it as one process (normal routine sending one email at a time) as it won't take long to process all the emails anyway. Doesn't seem right and I want to use threading... maybe I like complex routines?

[Extra]
I have something like:
foreach(string email in emailAddresses)
{
MailMessage mailMessage = new MailMessage();
mailMessage.To.Add(...)
...
SmtpClient client = new SmtpClient();
client.Send(mailMessage);
}