diff --git a/snappymail/v/0.0.0/app/libraries/RainLoop/ActionsAdmin.php b/snappymail/v/0.0.0/app/libraries/RainLoop/ActionsAdmin.php
index 3c7fee71b..65c2d433f 100644
--- a/snappymail/v/0.0.0/app/libraries/RainLoop/ActionsAdmin.php
+++ b/snappymail/v/0.0.0/app/libraries/RainLoop/ActionsAdmin.php
@@ -666,7 +666,7 @@ class ActionsAdmin extends Actions
 
 	private function setAdminAuthToken(string $sToken) : void
 	{
-		Utils::SetCookie(static::$AUTH_ADMIN_TOKEN_KEY, $sToken, 0);
+		Utils::SetCookie(static::$AUTH_ADMIN_TOKEN_KEY, $sToken);
 	}
 
 	private function getAdminToken() : string
diff --git a/snappymail/v/0.0.0/app/libraries/RainLoop/Api.php b/snappymail/v/0.0.0/app/libraries/RainLoop/Api.php
index fc056962f..136052449 100644
--- a/snappymail/v/0.0.0/app/libraries/RainLoop/Api.php
+++ b/snappymail/v/0.0.0/app/libraries/RainLoop/Api.php
@@ -80,7 +80,10 @@ abstract class Api
 			$sSslCapath = static::Config()->Get('ssl', 'capath', '');
 
 			Utils::$CookieDefaultPath = static::Config()->Get('labs', 'cookie_default_path', '');
-			Utils::$CookieDefaultSecure = !!static::Config()->Get('labs', 'cookie_default_secure', false);
+			Utils::$CookieSameSite = static::Config()->Get('security', 'cookie_samesite', 'Strict');
+			Utils::$CookieSecure = isset($_SERVER['HTTPS'])
+				|| 'None' == Utils::$CookieSameSite
+				|| !!static::Config()->Get('labs', 'cookie_default_secure', false);
 
 			if (!empty($sSslCafile) || !empty($sSslCapath))
 			{
diff --git a/snappymail/v/0.0.0/app/libraries/RainLoop/Config/Application.php b/snappymail/v/0.0.0/app/libraries/RainLoop/Config/Application.php
index 3f0fdfb3b..01ffc1baa 100644
--- a/snappymail/v/0.0.0/app/libraries/RainLoop/Config/Application.php
+++ b/snappymail/v/0.0.0/app/libraries/RainLoop/Config/Application.php
@@ -181,7 +181,8 @@ class Application extends \RainLoop\Config\AbstractConfig
 				'admin_panel_key'            => array('admin'),
 				'content_security_policy'    => array(''),
 				'csp_report'                 => array(false),
-				'encrypt_cipher'             => array($sCipher)
+				'encrypt_cipher'             => array($sCipher),
+				'cookie_samesite'            => array('Strict', 'Strict, Lax or None')
 			),
 
 			'admin_panel' => array(
diff --git a/snappymail/v/0.0.0/app/libraries/RainLoop/ServiceActions.php b/snappymail/v/0.0.0/app/libraries/RainLoop/ServiceActions.php
index fe30d4683..bf3e137ec 100644
--- a/snappymail/v/0.0.0/app/libraries/RainLoop/ServiceActions.php
+++ b/snappymail/v/0.0.0/app/libraries/RainLoop/ServiceActions.php
@@ -634,12 +634,14 @@ class ServiceActions
 		$this->oHttp->ServerNoCache();
 		$sTo = \trim($_GET['to'] ?? '');
 		if (!empty($sTo) && \preg_match('/^mailto:/i', $sTo)) {
-			Utils::SetCookie(Actions::AUTH_MAILTO_TOKEN_KEY,
+			Utils::SetCookie(
+				Actions::AUTH_MAILTO_TOKEN_KEY,
 				Utils::EncodeKeyValuesQ(array(
 					'Time' => \microtime(true),
 					'MailTo' => 'MailTo',
 					'To' => $sTo
-				)), 0);
+				))
+			);
 		}
 		$this->oActions->Location('./');
 		return '';
diff --git a/snappymail/v/0.0.0/app/libraries/RainLoop/Utils.php b/snappymail/v/0.0.0/app/libraries/RainLoop/Utils.php
index a41f317c4..3b4adf942 100644
--- a/snappymail/v/0.0.0/app/libraries/RainLoop/Utils.php
+++ b/snappymail/v/0.0.0/app/libraries/RainLoop/Utils.php
@@ -4,15 +4,11 @@ namespace RainLoop;
 
 class Utils
 {
-	/**
-	 * @var string
-	 */
 	static $CookieDefaultPath = '';
 
-	/**
-	 * @var bool|null
-	 */
-	static $CookieDefaultSecure = null;
+	static $CookieSecure = null;
+
+	static $CookieSameSite = 'Strict';
 
 	const
 		/**
@@ -119,7 +115,26 @@ class Utils
 			: null;
 	}
 
-	public static function SetCookie(string $sName, string $sValue = '', int $iExpire = 0, bool $bHttpOnly = true)
+	private static function _SetCookie(string $sName, string $sValue, int $iExpire)
+	{
+		$sPath = static::$CookieDefaultPath;
+		$sPath = $sPath && \strlen($sPath) ? $sPath : '/';
+/*
+		if (\strlen($sValue) > 4000 - \strlen($sPath . $sName)) {
+			throw new \Exception("Cookie '{$sName}' value too long");
+		}
+*/
+		\setcookie($sName, $sValue, array(
+			'expires' => $iExpire,
+			'path' => $sPath,
+//			'domain' => null,
+			'secure' => static::$CookieSecure,
+			'httponly' => true,
+			'samesite' => static::$CookieSameSite
+		));
+	}
+
+	public static function SetCookie(string $sName, string $sValue = '', int $iExpire = 0)
 	{
 		$sPath = static::$CookieDefaultPath;
 		$sPath = $sPath && \strlen($sPath) ? $sPath : '/';
@@ -133,14 +148,7 @@ class Utils
 		}
 */
 		foreach (\str_split($sValue, $iMaxSize) as $i => $sPart) {
-			\setcookie($i ? "{$sName}~{$i}" : $sName, $sPart, array(
-				'expires' => $iExpire,
-				'path' => $sPath,
-//				'domain' => $sDomain,
-				'secure' => isset($_SERVER['HTTPS']) || static::$CookieDefaultSecure,
-				'httponly' => $bHttpOnly,
-				'samesite' => 'Strict'
-			));
+			static::_SetCookie($i ? "{$sName}~{$i}" : $sName, $sPart, $iExpire);
 		}
 	}
 
@@ -151,14 +159,7 @@ class Utils
 			foreach (\array_keys($_COOKIE) as $sCookieName) {
 				if (\strtok($sCookieName, '~') === $sName) {
 					unset($_COOKIE[$sCookieName]);
-					\setcookie($sCookieName, '', array(
-						'expires' => \time() - 3600 * 24 * 30,
-						'path' => $sPath && \strlen($sPath) ? $sPath : '/',
-//						'domain' => null,
-						'secure' => isset($_SERVER['HTTPS']) || static::$CookieDefaultSecure,
-						'httponly' => true,
-						'samesite' => 'Strict'
-					));
+					static::_SetCookie($sCookieName, '', \time() - 3600 * 24 * 30);
 				}
 			}
 		}