I can't send email in network of my company

I can't send email in network of my company

I need help, in my company have a firewall bloked sending email
the code is
MailMessage msg = new MailMessage();
msg.From = new MailAddress("email@email.com", "Im");
msg.To.Add(new MailAddress("email@email.com", "SomeOne"));
msg.Subject = "This is a Test Mail";
msg.Body = "This is a test message using Exchange OnLine";
msg.IsBodyHtml = true;
SmtpClient client = new SmtpClient();
client.UseDefaultCredentials = true;
client.Credentials = new System.Net.NetworkCredential("my",
"secret");
client.Port = "587";
client.Host = "smtp.gmail.com";
client.DeliveryMethod = SmtpDeliveryMethod.Network;
client.EnableSsl = true;
try
{
client.Send(msg);
MessageBox.Show("Message Sent Succesfully");
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString());
}
}
strange that I have access to the gmail browser.
it is possible to cheat the firewall?