The server response was smtp.cyquator.com. Service not available closing transmission channel

                                                  Thread threadSendMails;                                                 threadSendMails = new Thread(delegate()                                                     {                                                         val = SendEmail.SendEMail(strFromAdd, strEmailAddress, strccadd, strFromAdd, strSubject, Body);                                                    });                                                 threadSendMails.IsBackground = true;                                                 threadSendMails.Start();

i use above code but my sendmail create all parameter null

and i also get The server response was  smtp.cyquator.com Service not available, closing transmission channel.  Error: too many connections

so which solution