diff --git a/snappymail/v/0.0.0/app/libraries/RainLoop/Providers/Files/FileStorage.php b/snappymail/v/0.0.0/app/libraries/RainLoop/Providers/Files/FileStorage.php
index e9781414b..f73cc3bce 100644
--- a/snappymail/v/0.0.0/app/libraries/RainLoop/Providers/Files/FileStorage.php
+++ b/snappymail/v/0.0.0/app/libraries/RainLoop/Providers/Files/FileStorage.php
@@ -55,16 +55,6 @@ class FileStorage implements \RainLoop\Providers\Files\IFiles
 		$bCreate = !!\preg_match('/[wac]/', $sOpenMode);
 
 		$sFileName = $this->generateFullFileName($oAccount, $sKey, $bCreate);
-		if (!\file_exists($sFileName)) {
-			$sOldFileName = $this->generateFullFileNameOld($oAccount, $sKey);
-			if (\file_exists($sOldFileName)
-			 && (
-				(!\is_dir(\dirname($sOldFileName)) && !\mkdir(\dirname($sOldFileName), 0700, true))
-				|| !\rename($sOldFileName, $sFileName)
-			)) {
-				$sFileName = $sOldFileName;
-			}
-		}
 		if ($bCreate || \file_exists($sFileName))
 		{
 			$mResult = \fopen($sFileName, $sOpenMode);
@@ -81,18 +71,12 @@ class FileStorage implements \RainLoop\Providers\Files\IFiles
 	public function GetFileName(\RainLoop\Model\Account $oAccount, string $sKey) /*: string|false*/
 	{
 		$sFileName = $this->generateFullFileName($oAccount, $sKey);
-		if (!\file_exists($sFileName)) {
-			$sFileName = $this->generateFullFileNameOld($oAccount, $sKey);
-		}
 		return \file_exists($sFileName) ? $sFileName : false;
 	}
 
 	public function Clear(\RainLoop\Model\Account $oAccount, string $sKey) : bool
 	{
 		$sFileName = $this->generateFullFileName($oAccount, $sKey);
-		if (!\file_exists($sFileName)) {
-			$sFileName = $this->generateFullFileNameOld($oAccount, $sKey);
-		}
 		if (\file_exists($sFileName)) {
 			if (isset($this->aResources[$sFileName]) && \is_resource($this->aResources[$sFileName])) {
 				\fclose($this->aResources[$sFileName]);
@@ -105,16 +89,12 @@ class FileStorage implements \RainLoop\Providers\Files\IFiles
 	public function FileSize(\RainLoop\Model\Account $oAccount, string $sKey) /*: int|false*/
 	{
 		$sFileName = $this->generateFullFileName($oAccount, $sKey);
-		if (!\file_exists($sFileName)) {
-			$sFileName = $this->generateFullFileNameOld($oAccount, $sKey);
-		}
 		return \file_exists($sFileName) ? \filesize($sFileName) : false;
 	}
 
 	public function FileExists(\RainLoop\Model\Account $oAccount, string $sKey) : bool
 	{
-		return \file_exists($this->generateFullFileName($oAccount, $sKey))
-			|| \file_exists($this->generateFullFileNameOld($oAccount, $sKey));
+		return \file_exists($this->generateFullFileName($oAccount, $sKey));
 	}
 
 	public function GC(int $iTimeToClearInHours = 24) : bool
@@ -180,39 +160,4 @@ class FileStorage implements \RainLoop\Providers\Files\IFiles
 		return $sFilePath;
 	}
 
-	private function generateFullFileNameOld(\RainLoop\Model\Account $oAccount, string $sKey, bool $bMkDir = false) : string
-	{
-		$sEmail = $sSubEmail = '';
-		if ($oAccount instanceof \RainLoop\Model\Account)
-		{
-			$sEmail = \preg_replace('/[^a-z0-9\-\.@]+/', '_', $oAccount->ParentEmailHelper());
-			if ($oAccount->IsAdditionalAccount())
-			{
-				$sSubEmail = \preg_replace('/[^a-z0-9\-\.@]+/', '_', $oAccount->Email());
-			}
-		}
-
-		if (empty($sEmail))
-		{
-			$sEmail = '__unknown__';
-		}
-
-		$sKeyPath = \sha1($sKey);
-		$sKeyPath = \substr($sKeyPath, 0, 2).'/'.\substr($sKeyPath, 2, 2).'/'.$sKeyPath;
-
-		$sFilePath = $this->sDataPath.'/'.
-			\str_pad(\rtrim(\substr($sEmail, 0, 2), '@'), 2, '_').'/'.$sEmail.'/'.
-			(0 < \strlen($sSubEmail) ? $sSubEmail.'/' : '').
-			$sKeyPath;
-
-		if ($bMkDir && !empty($sFilePath) && !\is_dir(\dirname($sFilePath)))
-		{
-			if (!\mkdir(\dirname($sFilePath), 0700, true))
-			{
-				throw new \RainLoop\Exceptions\Exception('Can\'t make storage directory "'.$sFilePath.'"');
-			}
-		}
-
-		return $sFilePath;
-	}
 }
diff --git a/snappymail/v/0.0.0/app/libraries/RainLoop/Providers/Storage/FileStorage.php b/snappymail/v/0.0.0/app/libraries/RainLoop/Providers/Storage/FileStorage.php
index 9496f7842..2a08367d3 100644
--- a/snappymail/v/0.0.0/app/libraries/RainLoop/Providers/Storage/FileStorage.php
+++ b/snappymail/v/0.0.0/app/libraries/RainLoop/Providers/Storage/FileStorage.php
@@ -49,13 +49,6 @@ class FileStorage implements \RainLoop\Providers\Storage\IStorage
 		$sFileName = $this->generateFileName($oAccount, $iStorageType, $sKey);
 		if ($sFileName && \file_exists($sFileName)) {
 			$mValue = \file_get_contents($sFileName);
-		} else {
-			$sFileName = $this->generateFileNameOld($oAccount, $iStorageType, $sKey);
-			if ($sFileName && \file_exists($sFileName)) {
-				$mValue = \file_get_contents($sFileName);
-				$this->Put($oAccount, $iStorageType, $sKey, $mValue);
-				\unlink($sFileName);
-			}
 		}
 
 		return false === $mValue ? $mDefault : $mValue;
@@ -70,11 +63,6 @@ class FileStorage implements \RainLoop\Providers\Storage\IStorage
 		$sFileName = $this->generateFileName($oAccount, $iStorageType, $sKey);
 		if ($sFileName && \file_exists($sFileName)) {
 			$mResult = \unlink($sFileName);
-		} else {
-			$sFileName = $this->generateFileNameOld($oAccount, $iStorageType, $sKey);
-			if ($sFileName && \file_exists($sFileName)) {
-				$mResult = \unlink($sFileName);
-			}
 		}
 
 		return $mResult;
@@ -89,17 +77,6 @@ class FileStorage implements \RainLoop\Providers\Storage\IStorage
 		if ($sPath && \is_dir($sPath)) {
 			\MailSo\Base\Utils::RecRmDir($sPath);
 		}
-
-		$sPath = $this->generateFileNameOld($oAccount, StorageType::USER, '', false, true);
-		if ($sPath && \is_dir($sPath)) {
-			\MailSo\Base\Utils::RecRmDir($sPath);
-		}
-
-		$sPath = $this->generateFileNameOld($oAccount, StorageType::CONFIG, '', false, true);
-		if ($sPath && \is_dir($sPath)) {
-			\MailSo\Base\Utils::RecRmDir($sPath);
-		}
-
 		return true;
 	}
 
@@ -147,6 +124,9 @@ class FileStorage implements \RainLoop\Providers\Storage\IStorage
 				if (empty($sEmail)) {
 					return '';
 				}
+				if (\is_dir("{$this->sDataPath}/cfg")) {
+					FixFileStorage::FixIt($this->sDataPath);
+				}
 				$aEmail = \explode('@', $sEmail ?: 'nobody@unknown.tld');
 				$sDomain = \trim(1 < \count($aEmail) ? \array_pop($aEmail) : '');
 				$sFilePath = $this->sDataPath
@@ -175,74 +155,6 @@ class FileStorage implements \RainLoop\Providers\Storage\IStorage
 		return $sFilePath;
 	}
 
-	/**
-	 * Old RainLoop structure
-	 */
-	private function generateFileNameOld($mAccount, int $iStorageType, string $sKey, bool $bMkDir = false, bool $bForDeleteAction = false) : string
-	{
-		if (null === $mAccount)
-		{
-			$iStorageType = StorageType::NOBODY;
-		}
-
-		$sEmail = $sSubEmail = '';
-		if ($mAccount instanceof \RainLoop\Model\Account)
-		{
-			$sEmail = $mAccount->ParentEmailHelper();
-			if ($this->bLocal && $mAccount->IsAdditionalAccount() && !$bForDeleteAction)
-			{
-				$sSubEmail = $mAccount->Email();
-			}
-		}
-
-		if (\is_string($mAccount) && empty($sEmail))
-		{
-			$sEmail = $mAccount;
-		}
-
-		$sEmail = \preg_replace('/[^a-z0-9\-\.@]+/i', '_', $sEmail);
-		$sSubEmail = \preg_replace('/[^a-z0-9\-\.@]+/i', '_', $sSubEmail);
-
-		$sTypePath = $sKeyPath = '';
-		switch ($iStorageType)
-		{
-			default:
-			case StorageType::USER:
-			case StorageType::NOBODY:
-				$sTypePath = 'data';
-				$sKeyPath = \md5($sKey);
-				$sKeyPath = \substr($sKeyPath, 0, 2).'/'.$sKeyPath;
-				break;
-			case StorageType::CONFIG:
-				$sTypePath = 'cfg';
-				$sKeyPath = \preg_replace('/[_]+/', '_', \preg_replace('/[^a-zA-Z0-9\/]/', '_', $sKey));
-				break;
-		}
-
-		$sFilePath = '';
-		if (StorageType::NOBODY === $iStorageType)
-		{
-			$sFilePath = $this->sDataPath.'/'.$sTypePath.'/__nobody__/'.$sKeyPath;
-		}
-		else if (!empty($sEmail))
-		{
-			$sFilePath = $this->sDataPath.'/'.$sTypePath.'/'.
-				\str_pad(\rtrim(\substr($sEmail, 0, 2), '@'), 2, '_').'/'.$sEmail.'/'.
-				(\strlen($sSubEmail) ? $sSubEmail.'/' : '').
-				($bForDeleteAction ? '' : $sKeyPath);
-		}
-
-		if ($bMkDir && !$bForDeleteAction && !empty($sFilePath) && !\is_dir(\dirname($sFilePath)))
-		{
-			if (!\mkdir(\dirname($sFilePath), 0700, true))
-			{
-				throw new \RainLoop\Exceptions\Exception('Can\'t make storage directory "'.$sFilePath.'"');
-			}
-		}
-
-		return $sFilePath;
-	}
-
 	public function SetLogger(?\MailSo\Log\Logger $oLogger)
 	{
 		$this->oLogger = $oLogger;
diff --git a/snappymail/v/0.0.0/app/libraries/RainLoop/Providers/Storage/FixFileStorage.php b/snappymail/v/0.0.0/app/libraries/RainLoop/Providers/Storage/FixFileStorage.php
new file mode 100644
index 000000000..9edf15120
--- /dev/null
+++ b/snappymail/v/0.0.0/app/libraries/RainLoop/Providers/Storage/FixFileStorage.php
@@ -0,0 +1,47 @@
+<?php
+
+namespace RainLoop\Providers\Storage;
+
+abstract class FixFileStorage
+{
+
+	/**
+	 * Replace control characters, ampersand, spaces and reserved characters (based on Win95 VFAT)
+	 * en.wikipedia.org/wiki/Filename#Reserved_characters_and_words
+	 */
+	private static function fixName($filename)
+	{
+		return \preg_replace('#[|\\\\?*<":>+\\[\\]/&\\s\\pC]#su', '-', $filename);
+	}
+
+	public static function FixIt(string $sDataPath)
+	{
+		// /cfg/ex/example@example.com
+		foreach (\glob("{$sDataPath}/cfg/*", GLOB_ONLYDIR) as $sOldDir) {
+			foreach (\glob("{$sOldDir}/*", GLOB_ONLYDIR) as $sDomainDir) {
+				$aEmail = \explode('@', \basename($sDomainDir));
+				$sDomain = \trim(1 < \count($aEmail) ? \array_pop($aEmail) : '');
+				$sNewDir = $sDataPath
+					.'/'.static::fixName($sDomain ?: 'unknown.tld')
+					.'/'.static::fixName(\implode('@', $aEmail) ?: '.unknown');
+				if (\is_dir($sNewDir) || \mkdir($sNewDir, 0700, true)) {
+					foreach (\glob("{$sDomainDir}/*") as $sItem) {
+						$sName = \basename($sItem);
+						if ('sign_me' === $sName) {
+							// Security issue
+							// https://github.com/RainLoop/rainloop-webmail/issues/2133
+							\unlink($sItem);
+						} else {
+							\rename($sItem, "{$sNewDir}/{$sName}");
+						}
+					}
+					\MailSo\Base\Utils::RecRmDir($sDomainDir);
+				}
+			}
+		}
+		\MailSo\Base\Utils::RecRmDir("{$sDataPath}/cfg");
+		\MailSo\Base\Utils::RecRmDir("{$sDataPath}/data");
+		\MailSo\Base\Utils::RecRmDir("{$sDataPath}/files");
+	}
+
+}