Android - programmatically read incoming / outgoing emails for google account (Gmail app installed / not installed)

I am trying to read incoming / outgoing emails from my main google account. But I cannot do this. I followed the source code (it was installed for the Gmail app)

ContentResolver cr = getContentResolver(); 
Cursor unread = cr.query(Uri.parse("content://gmail-ls/conversations/xxxxxx@gmail.com"), null, "label:^u", null, null); 
unread.moveToFirst(); 
int subjectIdx = unread.getColumnIndex("subject");

do {
   String subject = unread.getString(subjectIdx); 
} while (unread.moveToNext());

      

        
        
        
      

    

taken from a question from stackoverflow (forgot link, I feel bad) but it doesn't work. Is there a way to read incoming / outgoing email for the main google account.