Как получить smtpclient в нашей компании ?

I WORK at ABC Company . and I was assigned to make an application to send an email to employees .
I try browsing and the following code :

public void Send(MailMessage msg)
        {
            SmtpClient client = new SmtpClient("smtp.gmail.com", 587);
            client.EnableSsl = true;
            client.DeliveryMethod = SmtpDeliveryMethod.Network;
            client.Credentials = new NetworkCredential(Username, Password);
            client.Send(msg);
        }

when I run, it does work well . but the email server that I would use is the domain of companies that Rudi_Bastian@abc.com
How do I get my company SmtpClient it ?

may be the master here can help me .