A simple program using smtp for sending gmail

#include "stdafx.h"
#include <stdio.h>
#include <stdlib.h>
#using <System.dll>

using namespace System;
using namespace System::Net::Sockets;
using namespace System::Collections;
using namespace System::Collections::Generic;
using namespace System::Text;
using namespace System::IO;
using namespace System::Net;
using namespace System::Net::Mail;
using namespace System::Net::Mime;
using namespace System::Threading;
using namespace System::ComponentModel;

namespace GMailSend
{
 //array: http://msdn.microsoft.com/zh-tw/library/ms235236.aspx
 void Send(String^ from, String^ to, String^ subject, String^ body, 
  array<System::String ^>^ cc, int cc_num, array<System::String ^>^ bcc, int bcc_num, String^ host, int port, 
  String^ smtpUsername, String^ smtpPassword)
 {
  // Create mail message
  MailMessage^ message = gcnew MailMessage(from, to, subject, body);
  message->BodyEncoding = System::Text::Encoding::UTF8;

  if (cc != nullptr && cc_num > 0)
  {
   for(int i=0; i<cc_num; i++)
   {
    message->CC->Add(gcnew MailAddress(cc[i]));
   }
  }
  if (bcc != nullptr && bcc_num > 0)
  {
   for(int i=0; i<bcc_num; i++)
   {
    message->Bcc->Add(gcnew MailAddress(bcc[i]));
   }
  }

  // Send email
  SmtpClient^ client = gcnew SmtpClient(host, port);
  if (!String::IsNullOrEmpty(smtpUsername) && !String::IsNullOrEmpty(smtpPassword))
  {
   client->Credentials = gcnew NetworkCredential(smtpUsername, smtpPassword);
  }
  client->EnableSsl = true;
  client->Send(message);
 }

}

int _tmain(int argc, _TCHAR* argv[])
{


 GMailSend::Send("from@gmail.com","to@hotmail.com",  "testsubject", "testbodymessage", nullptr, 0, nullptr, 0, 
  "smtp.gmail.com", 587, "gmail_account", "gmail_password");


 system("pause");
 return 0;
}

#include "stdafx.h"
#include <stdio.h>
#include <stdlib.h>
#using <System.dll>

using namespace System;
using namespace System::Net::Sockets;
using namespace System::Collections;
using namespace System::Collections::Generic;
using namespace System::Text;
using namespace System::IO;
using namespace System::Net;
using namespace System::Net::Mail;
using namespace System::Net::Mime;
using namespace System::Threading;
using namespace System::ComponentModel;


#define GMail_DEBUG

String^ showUsage() {
 StringBuilder^ sb = gcnew StringBuilder();

 sb->AppendLine( "Usage: MailSharp [options] ToAddress" );
 sb->AppendLine( "\t-a File to attach." );
 sb->AppendLine( "\t-f From address" );
 sb->AppendLine( "\t-b Body message" );
 sb->AppendLine( "\t-s Subject");
 sb->AppendLine( "\t-S SMTP server host" );
 sb->AppendLine( "\t-U Username for SMTP server authentication" );
 sb->AppendLine( "\t-p Password for SMTP server authentication" );
 sb->AppendLine( "\t-P SMTP server port" );
 sb->AppendLine( "\t-l Use SSL" );
 sb->AppendLine( "\t-h Help/Usage");
 sb->AppendLine();
 sb->AppendLine( "Example:" );
 sb->AppendLine( "\tFor GMail" );
 sb->AppendLine( "\tMailSharp -f your_name@gmail.com -b MessageBody -s TestSubject -S smtp.gmail.com -P 587 -l -U your_gmail -p your_gmail_password -t someone@somewhere.com" );
#ifdef GMail_DEBUG 
 // Display the number of characters in the StringBuilder and its string.
 Console::WriteLine("{0} chars: {1}", sb->Length, sb->ToString());
#endif

 return sb->ToString();
}




int _tmain(int argc, _TCHAR* argv[])
{

 //showUsage();
 MailAddress^ from = nullptr;
 MailAddress^ to = nullptr;
 MailMessage^ message = gcnew MailMessage();
 SmtpClient^ client = gcnew SmtpClient();
 NetworkCredential^ myCred = gcnew NetworkCredential();
 bool bShowUsage=false;

 try{
  if ( argc > 0 ) {
   for ( int i=0; i<argc; i++ ) {
    if( argv[i][0] == '-' ){
     switch ( argv[i][1] ) {
     case 'S': // server host
      i++;
      if ( i<argc ) {
       client->Host = gcnew String(argv[i]);
      } else
       throw gcnew Exception( "-S was specified, but no value." );
      break;
     case 'P': // server port
      i++;
      if ( i<argc ) {
       client->Port= Convert::ToInt32( gcnew String(argv[i]) );
      } else
       throw gcnew Exception( "-P was specified, but no value." );
      break;
     case 'T': // timeout
      i++;
      if ( i<argc ) {
       client->Timeout = Convert::ToInt32( gcnew String(argv[i]) );
      } else
       throw gcnew Exception( "-T was specified, but no value." );
      break;
     case 'U': // username for smtp server authentication
      i++;
      if ( i<argc )
       myCred->UserName = gcnew String(argv[i]);
      else
       throw gcnew Exception( "-U was specified, but no value." );
      break;
     case 'p': // password for smtp server authentication
      i++;
      if ( i<argc )
       myCred->Password = gcnew String(argv[i]);
      else
       throw gcnew Exception( "-p was specified, but no value." );
      break;
     case 'l': // use SSL
      client->EnableSsl = true;
      break;
     case 's': // subject
      i++; // next one is subject.
      if ( i<argc ) {
       message->Subject = gcnew String(argv[i]);
       message->SubjectEncoding = System::Text::Encoding::UTF8;
      } else
       throw gcnew Exception( "-s was specified, but no value." );
      break;
     case 'a': // attachment
      i++; // next one is attachment filename.
      if ( i<argc ) {
       // Add attachment.
       Attachment^ data = gcnew Attachment( gcnew String(argv[i]), MediaTypeNames::Application::Octet);
       message->Attachments->Add(data);
      } else
       throw gcnew Exception( "-a was specified, but no value." );
      break;
     case 'b': // body message.
      i++; // next one is body message
      if ( i<argc ) {
       message->Body = gcnew String(argv[i]);
       message->BodyEncoding =  System::Text::Encoding::UTF8;
      } else
       throw gcnew Exception( "-b was specified, but no value." );
      break;
     case 'f': // from address
      i++;
      if ( i<argc ) {
       // Specify the e-mail sender.
       // Create a mailing address that includes a UTF8 character
       // in the display name.
       // from = new MailAddress( "someone@gmail.com", "someone", System.Text.Encoding.UTF8);
       from = gcnew MailAddress( gcnew String(argv[i]) );
      } else
       throw gcnew Exception( "-f was specified, but no value." );
      break;
     case 'h': // show help/usage
      bShowUsage=true;
      break;
     case 't':
      i++;
      to = gcnew MailAddress( gcnew String(argv[i]) );
      break;
     }//end of switch
    }//end of check '-'
   }//end of for
  } else
   throw gcnew Exception("No arguments.");
 }catch(Exception^ ex){
  Console::WriteLine( ex->Message );
  bShowUsage = true;
 }

 try {
  if ( bShowUsage == true )
   throw gcnew Exception( showUsage() );

  if ( from==nullptr )
   throw gcnew Exception( "Must specify from address (-f)." );

  // Set destinations for the e-mail message.
  if ( to == nullptr )
   throw gcnew Exception("At least, must specify to address");

  if ( client->Host == String::Empty )
   throw gcnew Exception("Must specify SMTP Server (-S)." );

  // Specify the message content.
  message->From = from;
  message->To->Add( to );

  // Credentials are necessary if the server requires the client
  // to authenticate before it will send e-mail on the client's behalf.
  //client.UseDefaultCredentials = false;
  client->Credentials = myCred;

  // Send.
  // If you need asynchronous sample, please visit the reference above.
  client->Send(message);

  Console::WriteLine("Done.");
 } catch ( Exception^ ex ) {
  Console::WriteLine( "Exception was raised when sending...");
  Console::WriteLine( ex->Message );
 } finally {
  // Clean up.
  message->~MailMessage();
 }


 system("pause");
 return 0;
}