asp.net - Sending a message with C# works locally but silently fails live -

hi, using following code send booking form working locally when put live fails , not sure why:

protected void page_load(object sender, eventargs e) {

} protected void sendmail() {     var sdate = startdate.text;     var edate = enddate.text;      // gmail address send mail     var fromaddress = "xxx@googlemail.com";     // address email sending     var toaddress = "silverhillcattery@hotmail.co.uk";     //password of gmail address     const string frompassword = "xxx";     // passing values , make email formate display     string subject = yoursubject.text.tostring();     string body = "from: " + yourname.text + "\n";     body += "email: " + youremail.text + "\n";     body += "contact number: " + txtcontactnumber.text + "\n";     body += "subject: " + yoursubject.text + "\n";     body += "question: \n" + comments.text + "\n";     body += "pet name(s): \n" + txtpetname.text + "\n";     body += "start date: \n" + sdate + "\n";     body += "end date: \n" + edate + "\n";      // smtp settings     var smtp = new system.net.mail.smtpclient();     {         smtp.host = "smtp.gmail.com";         smtp.port = 587;         smtp.enablessl = true;         smtp.deliverymethod = system.net.mail.smtpdeliverymethod.network;         smtp.credentials = new networkcredential(fromaddress, frompassword);         smtp.timeout = 20000;     }     // passing values smtp object     smtp.send(fromaddress, toaddress, subject, body); }  protected void button1_click(object sender, eventargs e) {     try     {         //here on button click done          sendmail();         displaymessage.text = "thank contacting shortly.  if talk us, please call 0208 236 9572";         displaymessage.visible = true;         yoursubject.text = "";         youremail.text = "";         yourname.text = "";         comments.text = "";     }     catch (exception) { } } 

it doesn't send message or display "thank contacting..."

this site www.silverhillcattery.co.uk

any appreciated!

update:

i have added error message suggested , following error:

"the smtp server requires secure connection or client not authenticated"

i issue.

i can guess credentials work in local environment don't in live environment. if code fails exception on send bypass display code , go directly "catch" code.

to debug it, put send after display see happens or more appropriately modify catch (exception) grab error , display that.

catch (exception ex)  {           displaymessage.text = "failed send email. error = " + ex.message;         displaymessage.visible = true; }