diff --git a/rainloop/v/0.0.0/app/libraries/MailSo/Base/Crypt.php b/rainloop/v/0.0.0/app/libraries/MailSo/Base/Crypt.php
index f21bdbca9..152a0c902 100644
--- a/rainloop/v/0.0.0/app/libraries/MailSo/Base/Crypt.php
+++ b/rainloop/v/0.0.0/app/libraries/MailSo/Base/Crypt.php
@@ -31,6 +31,10 @@ class Crypt
 			return '';
 		}
 
+		if (\is_callable('xxtea_encrypt')) {
+			return xxtea_encrypt($sString, $sKey);
+		}
+
 		$aV = self::str2long($sString, true);
 		$aK = self::str2long($sKey, false);
 		if (\count($aK) < 4)
@@ -80,6 +84,10 @@ class Crypt
 			return '';
 		}
 
+		if (\is_callable('xxtea_decrypt')) {
+			return xxtea_decrypt($sEncriptedString, $sKey);
+		}
+
 		$aV = self::str2long($sEncriptedString, false);
 		$aK = self::str2long($sKey, false);
 
@@ -186,4 +194,4 @@ class Crypt
 		}
 		return (int) $iN;
 	}
-}
\ No newline at end of file
+}