Hi marcel, I modified the code as you said. I'm unable to
revert the operation after receiving the file, the contents
gets deleted, Can you please check the code below.


//Sending message------>
Qt Code: 
  1. void SynsupMail::sendMessage()
  2. {
  4. 	string msg;
  5.        	QFile f ( textFilename->text() );
  6.       	if ( f.open (IO_ReadOnly) )
  7.       	{   
  8.         	  // file opened successfully   
  9.           	dat = f.readAll();
  10.       	} 
  11. 	else
  12. 	{
  13. 		// problems opening the file - emit a warning message
  14. 		QMessageBox::warning( this, tr("error"), 
  15. 			tr("Error opening file %1").arg( textFilename->text() ) );
  16. 		enableSubmit();
  17. 		return;
  18. 	}	
  19. 	f.close();
  20. 	StringSource ( string(QString(dat).data()), true, new Base64Encoder(new StringSink(msg))); 
  21. 	Smtp *smtp = new Smtp( textFrom->text(), textTo->text(),
  22. 		textSubject->text(),
  23. 		QString(msg.data()), fileName );
  24. }
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Qt Code: 
  1. Smtp::Smtp( const QString &from, const QString &to,
  2. 		const QString &subject,
  3. 		const QString &body, const QString &fileName)
  4. 	{
  5. 		address = QString::fromLatin1( "From: " ) + from +
  6. 	 		 QString::fromLatin1( "\nTo: " ) + to +
  7. 	 		 QString::fromLatin1( "\nSubject: " ) + subject + "\n";
  8.  
  9. 	 	message = QString::fromLatin1( "\n\n" ) + body + "\n";
  10.  
  11. 	 	/*replace( message, QString::fromLatin1( "\n" ),
  12. 	 		 QString::fromLatin1( "\r\n" ) );*/
  13. 	 	replace( message, QString::fromLatin1( "\r\n.\r\n" ),
  14. 	 		 QString::fromLatin1( "\r\n..\r\n" ) );
  15. 	 	replace( address, QString::fromLatin1( "\n" ),
  16. 	 		 QString::fromLatin1( "\r\n" ) );
  17. 	 	replace( address, QString::fromLatin1( "\r\n.\r\n" ),
  18. 	 		 QString::fromLatin1( "\r\n..\r\n" ) );
  19. 	}
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//Receiving message------>
Qt Code: 
  1. int SysupClass::openFile( const char* infile )
  2. {
  4.        	QFile f ( infile );
  5.       	if ( f.open (IO_ReadOnly) )
  6.       	{   
  7.         	  // file opened successfully   
  8.           	dat = f.readAll();
  9.       	} 
  10. 	else 
  11. 	{
  12. 		f.close();
  13. 		return -1;
  14. 	}
  15. 	f.close();
  16.  
  17. 	//Here I might not be correct to reverse the operation
  18. 	//i.e removing \r\n..\r\n 	
  19. 	/*QString ss = dat;
  20. 	replace( ss, QString::fromLatin1( "\r\n..\r\n" ),
  21.                      QString::fromLatin1( "\r\n.\r\n" ) );*/
  22.  
  23. 	QFile f1 ( strcat(infile, ".mod") );
  24. 	if ( f1.open (IO_WriteOnly|IO_Truncate) )
  25. 		{
  26. 		// file opened successfully
  27. 		f1.writeBlock(ss, ss.length());
  28. 		}
  29. 	f1.close();
  30.  
  31. 	//decrypt the file with AES::CBC mode
  32. }
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wysota--->
I'm unable to understand these points
3. divide it into blocks 64 (or 80 or whatever) bytes each ---- need some more explanation
4. concatenate blocks using newlines (\r\n) ----- ---- need some more explanation
5. pass the result into the mail stream adding a base64 header --------- ---- need some more explanations
If possible please correct me with my code above and tell me how can I achieve the above three points