If i use the code what is attached in post and post the message from page if its default locale it works using aadress:
http://mysite/element-majad/element-b-83/?success=1 (locale is estonian)

If i use the same page in english just translated and the aadress of the page is:
http://mysite/standard-designs/element-b-83-en-US/
but when i use the form there it redirects after sending message to
http://mysite/element-b-83-en-US/?success=1

it needs to be http://mysite/standard-designs/element-b-83-en-US/?success=1 to show the page

Using code in contact from:

<?php
/**
 * Defines the Maja page type
 */
class Maja extends Page {
   static $db = array(
	'Pindala' => 'Text',
	'Tubasid' => 'Text',
	'Korruseid' => 'Text'
   );
   static $has_one = array(
	'MajaPilt' => 'Image',
	'Plaan' => 'Image',
	'Plaan2' => 'Image',
	'Plaan3' => 'Image',
	'Maja360' => 'File',
	'Spets' => 'File',
	'Spets2' => 'File'
   );
function getCMSFields() {
    $fields = parent::getCMSFields();
	$fields->addFieldToTab('Root.Content.Pilt', new ImageField('MajaPilt','Maja Pilt'));
	$fields->addFieldToTab('Root.Content.Main', new ImageField('Plaan','Esimene plaan'), 'Content');
	$fields->addFieldToTab('Root.Content.Main', new ImageField('Plaan2','Teine plaan'), 'Content');
	$fields->addFieldToTab('Root.Content.Main', new ImageField('Plaan3','Kolmas plaan'), 'Content');
	$fields->addFieldToTab('Root.Content.Main', new FileIFrameField('Maja360','Maja 360 vaade'), 'Content');
	$fields->addFieldToTab('Root.Content.Main', new FileIFrameField('Spets','Spetsi PDF'), 'Content');
	$fields->addFieldToTab('Root.Content.Main', new FileIFrameField('Spets2','2 Spetsi PDF'), 'Content');
	$fields->addFieldToTab('Root.Content.Main', new TextField('Pindala','Hoone pindala'), 'Content');
	$fields->addFieldToTab('Root.Content.Main', new TextField('Tubasid','Tubade arv'), 'Content');
	$fields->addFieldToTab('Root.Content.Main', new TextField('Korruseid','Korruste arv'), 'Content');
        return $fields;
    }
} 
 
class Maja_Controller extends Page_Controller {
static $allowed_actions = array( 
      'MajaForm' 
   ); 
    
   function MajaForm(){ 
   $fields = new FieldSet( 
         new EmailField('Email', _t("FORM24.EMAIL","Teie e-post:") ),  
         new Textareafield('Message', _t("FORM24.MESSAGE","Teie s&otilde;num:") )
);
      $actions = new FieldSet(new FormAction('SendMajaForm',_t("FORM24.SEND","Saada") )); 
      $validator = new RequiredFields( 
         'Message', 
         'Email' 
      ); 
      return new Form($this, 'MajaForm', $fields, $actions, $validator); 
   } 



   function SendMajaForm($data, $form){
   	 	//Set data
		$From = $data['Email'];
		$To = "info@elementmajatehas.ee";
		$Subject = "$this->Title"; 	  
		$email = new Email($From, $To, $Subject);
		//set template
		$email->setTemplate('MajaEmail');
		//populate template
		$email->populateTemplate($data);
		//send mail
		$email->send();
	  	//return to submitted message
		Director::redirect(Director::baseURL(). $this->URLSegment . "/?success=1");

	}
	//The function to test whether to display the Submit Text or not
	public function Success()
	{
		return isset($_REQUEST['success']) && $_REQUEST['success'] == "1";
	} 
} 
?>

You shouldn't rely on things like Director::baseURL(). $this->URLSegment. All pages (and most dataobjects) should define a Link() and an AbsoluteLink() method for getting the URL of the object.

Try something like

Director::redirect($this->Link() . "?success=1");