c# - correct code for sending an email, asp.net -

i have form allows user send email on mailing list (linq table). i'm having trouble correct code , syntax linking smtp server.

using system; using system.collections.generic; using system.linq; using system.web; using system.web.ui; using system.web.ui.webcontrols; using system.web.profile; using system.web.security; using system.web.mail; using system.configuration; using system.web.configuration; using system.net.configuration; using system.net.mail;    public partial class massemail : system.web.ui.page {     protected void page_load(object sender, eventargs e)     {      }     protected void button1_click(object sender, eventargs e)     {          mailinglistclassdatacontext class = new mailinglistclassdatacontext();         var emaillist = emails in class.mailinglistmembers select emails.email;          foreach (var subcriber in emaillist)         {                   mailmessage objmail = new mailmessage();                 objmail.from = "test@test.com";                  objmail.to = subcriber;                  objmail.bodyformat = mailformat.html ;                   //the subject of message                  objmail.subject = "test email hope works" ;                  //he message text                  objmail.body = editor1.content;                  //need in area                 smtpclient client = new smtpclient();                  smtpclient.send(objmail);                  }             } } 

using (var db = new mailinglistclassdatacontext()) {     var client = new system.net.mail.smtpclient();      var recipients = e in db.mailinglistmembers                      select e.email;      foreach (string recipient in recipients)     {         var message = new system.net.mail.mailmessage("sender@example.com", recipient);         message.subject = "hello world!";         message.body = "<h1>foo bar</h1>";         message.isbodyhtml = true;         client.send(message);     } } 

try setting configuration in web.config or machine.config. make sure you've specified correct address , port of smtp server.

<configuration>   <system.net>     <mailsettings>       <smtp deliverymethod="network" from="me@example.com">         <network           host="localhost"           port="25"           defaultcredentials="true"         />       </smtp>     </mailsettings>   </system.net> </configuration>