diff --git a/mail/inc/class.mail_hooks.inc.php b/mail/inc/class.mail_hooks.inc.php
index d64fdad4c9..78ee57887e 100644
--- a/mail/inc/class.mail_hooks.inc.php
+++ b/mail/inc/class.mail_hooks.inc.php
@@ -440,7 +440,8 @@ class mail_hooks
 					'expand' => lang('show horizontal, hide if none selected'),
 					'hide' => lang('never show'),
 				),
-				'default' => 'vertical'
+				'default' => 'vertical',
+				'reload' => true
 			),
 			'toggledOnActions' => array(
 				'type' => 'taglist',
diff --git a/preferences/inc/class.preferences_hooks.inc.php b/preferences/inc/class.preferences_hooks.inc.php
index c924ac1858..d67572722b 100644
--- a/preferences/inc/class.preferences_hooks.inc.php
+++ b/preferences/inc/class.preferences_hooks.inc.php
@@ -184,6 +184,7 @@ class preferences_hooks
 				'values' => $textsize,
 				'default' => '14',
 				'admin'  => False,
+				'reload' => true
 			),
 			'lazy-update' => array(
 				'type'   => 'select',
@@ -205,6 +206,7 @@ class preferences_hooks
 				'xmlrpc' => True,
 				'admin'  => False,
 				'forced' => file_exists(EGW_SERVER_ROOT.'/pixelegg') ? 'pixelegg' : 'idots',
+				'reload' => true
 			),
 			'theme' => array(
 				'type'   => 'select',
@@ -215,6 +217,7 @@ class preferences_hooks
 				'xmlrpc' => True,
 				'admin'  => False,
 				'forced' => file_exists(EGW_SERVER_ROOT.'/pixelegg') ? 'pixelegg' : 'idots',
+				'reload' => true
 			),
 			'darkmode' => array(
 				'type'   => 'select',
@@ -335,6 +338,7 @@ class preferences_hooks
 				'xmlrpc' => True,
 				'admin'  => False,
 				'default'=> $lang,
+				'reload' => true
 			),
 			'country' => array(
 				'type'       => 'et2-select-country',
diff --git a/preferences/inc/class.preferences_settings.inc.php b/preferences/inc/class.preferences_settings.inc.php
index 0732760715..d100c731b1 100644
--- a/preferences/inc/class.preferences_settings.inc.php
+++ b/preferences/inc/class.preferences_settings.inc.php
@@ -99,25 +99,25 @@ class preferences_settings
 							$GLOBALS['egw']->preferences->set_account_id($account_id);
 							$GLOBALS['egw']->preferences->read_repository();
 						}
-						// name of common preferences which require reload of framework, if there values change
-						$require_reload = array('template_set', 'theme', 'lang', 'template_color', 'template_custom_color', 'textsize');
-						$old_values = array_intersect_key($GLOBALS['egw_info']['user']['preferences']['common'], array_flip($require_reload));
-
 						$attribute = $type == 'group' ? 'user' : $type;
+
+						$require_reload = self::fetchRequireToReload($appname, $type);
+						$old_values = array_intersect_key($GLOBALS['egw_info']['user']['preferences'][$appname], array_flip($require_reload));
+
 						if (!($msg=$this->process_array($GLOBALS['egw']->preferences->$attribute, $prefs, $content['types'], $appname, $attribute, $content)))
 						{
 							$msg_type = 'success';
 							$msg = lang('Preferences saved.');
 
 							// do we need to reload whole framework
-							if ($appname == 'common')
+							if (!empty($require_reload))
 							{
 								if ($account_id && $GLOBALS['egw']->preferences->get_account_id() != $GLOBALS['egw_info']['user']['account_id'])
 								{
 									$GLOBALS['egw']->preferences->set_account_id($GLOBALS['egw_info']['user']['account_id']);
 								}
 								$GLOBALS['egw_info']['user']['preferences'] = $GLOBALS['egw']->preferences->read_repository();
-								$new_values = array_intersect_key($GLOBALS['egw_info']['user']['preferences']['common'], array_flip($require_reload));
+								$new_values = array_intersect_key($GLOBALS['egw_info']['user']['preferences'][$appname], array_flip($require_reload));
 								//error_log(__METHOD__."() ".__LINE__.": old_values=".array2string($old_values).", new_values=".array2string($new_values));
 								if ($old_values != $new_values)
 								{
@@ -199,6 +199,41 @@ class preferences_settings
 		$tpl->exec('preferences.preferences_settings.index', $data, $sel_options, $readonlys, $preserve, 2);
 	}
 
+	/**
+	 * Fetch preferences of given app where they have reload attribute set to true
+	 * @param string $appname app name
+	 * @param string $type 'user', 'default', 'forced'
+	 * @return array
+	 * @throws Api\Exception\AssertionFailed
+	 */
+	static function fetchRequireToReload($appname, $type)
+	{
+		$keys = [];
+		if ($appname == 'common')
+		{
+			// none app pref names here since we can't read them via hooks
+			$keys = ['template_color', 'template_custom_color', 'sidebox_custom_color'];
+			$settings = Api\Hooks::single(array(
+				'account_id'=>$GLOBALS['egw']->preferences->get_account_id(),
+				'location'=>'settings',
+				'type' => $type), 'preferences');
+		}
+		else
+		{
+			$settings = Api\Hooks::single(array(
+				'account_id'=>$GLOBALS['egw']->preferences->get_account_id(),
+				'location'=>'settings',
+				'type' => $type), $appname);
+		}
+
+
+		foreach ($settings as $key => $value)
+		{
+			if ($value['reload']) $keys[]=$key;
+		}
+		return $keys;
+	}
+
 	/**
 	 * run admin command instance
 	 *