diff --git a/application/Espo/Core/Mail/Account/Fetcher.php b/application/Espo/Core/Mail/Account/Fetcher.php
index eb2f095c02..97a86bed1b 100644
--- a/application/Espo/Core/Mail/Account/Fetcher.php
+++ b/application/Espo/Core/Mail/Account/Fetcher.php
@@ -29,12 +29,12 @@
 
 namespace Espo\Core\Mail\Account;
 
-use Laminas\Mail\Storage;
-
 use Espo\Core\Exceptions\Error;
+
+use Espo\Core\Mail\Account\Storage\Flag;
+use Espo\Core\Mail\Account\Storage;
 use Espo\Core\Mail\Importer;
 use Espo\Core\Mail\Importer\Data as ImporterData;
-use Espo\Core\Mail\Mail\Storage\Imap;
 use Espo\Core\Mail\ParserFactory;
 use Espo\Core\Mail\MessageWrapper;
 use Espo\Core\Mail\Account\Hook\BeforeFetch as BeforeFetchHook;
@@ -44,6 +44,7 @@ use Espo\Core\Mail\Account\Hook\BeforeFetchResult as BeforeFetchHookResult;
 use Espo\Core\Utils\DateTime as DateTimeUtil;
 use Espo\Core\Utils\Config;
 use Espo\Core\Utils\Log;
+use Espo\Core\Field\DateTime as DateTimeField;
 
 use Espo\Entities\EmailFilter;
 use Espo\Entities\Email;
@@ -121,7 +122,7 @@ class Fetcher
     private function fetchFolder(
         Account $account,
         string $folderOriginal,
-        Imap $storage,
+        Storage $storage,
         Collection $filterList
     ): void {
 
@@ -130,7 +131,7 @@ class Fetcher
         $folder = mb_convert_encoding($folderOriginal, 'UTF7-IMAP', 'UTF-8');
 
         try {
-            $storage->selectFolder($folder);
+            $storage->selectFolder($folderOriginal);
         }
         catch (Throwable $e) {
             $this->log->error(
@@ -211,7 +212,7 @@ class Fetcher
 
         if ($forceByDate) {
             if ($previousLastUID) {
-                $idList = $storage->getIdsFromUID($previousLastUID);
+                $idList = $storage->getIdsFromUniqueId($previousLastUID);
 
                 if (count($idList)) {
                     $uid1 = $storage->getUniqueId($idList[0]);
@@ -234,14 +235,14 @@ class Fetcher
      */
     private function getIdList(
         Account $account,
-        Imap $storage,
+        Storage $storage,
         ?string $lastUID,
         ?string $lastDate,
         bool $forceByDate
     ): array {
 
         if (!empty($lastUID) && !$forceByDate) {
-            return $storage->getIdsFromUID($lastUID);
+            return $storage->getIdsFromUniqueId($lastUID);
         }
 
         if ($lastDate) {
@@ -255,8 +256,8 @@ class Fetcher
             $fetchSince = $account->getFetchSince()->getString();
         }
 
-        return $storage->getIdsFromDate(
-            (new DateTime($fetchSince))->format('d-M-Y')
+        return $storage->getIdsSinceDate(
+            DateTimeField::fromString($fetchSince)
         );
     }
 
@@ -265,7 +266,7 @@ class Fetcher
      */
     private function fetchEmail(
         Account $account,
-        Imap $storage,
+        Storage $storage,
         int $id,
         Collection $filterList
     ): ?Email {
@@ -297,7 +298,7 @@ class Fetcher
             ->withAssignedUserId($assignedUserId);
 
         try {
-            $message = new MessageWrapper($storage, (string) $id, $parser);
+            $message = new MessageWrapper($id, $storage, $parser);
 
             $hookResult = null;
 
@@ -318,9 +319,9 @@ class Fetcher
             if (
                 $account->keepFetchedEmailsUnread() &&
                 is_array($flags) &&
-                empty($flags[Storage::FLAG_SEEN])
+                empty($flags[Flag::SEEN])
             ) {
-                unset($flags[Storage::FLAG_RECENT]);
+                unset($flags[Flag::RECENT]);
 
                 $storage->setFlags($id, $flags);
             }
@@ -395,7 +396,7 @@ class Fetcher
             ->find();
     }
 
-    private function checkFetchOnlyHeader(Imap $storage, int $id): bool
+    private function checkFetchOnlyHeader(Storage $storage, int $id): bool
     {
         $maxSize = $this->config->get('emailMessageMaxSize');
 
diff --git a/application/Espo/Core/Mail/Account/GroupAccount/Service.php b/application/Espo/Core/Mail/Account/GroupAccount/Service.php
index 06f41c7b7f..197022f0f8 100644
--- a/application/Espo/Core/Mail/Account/GroupAccount/Service.php
+++ b/application/Espo/Core/Mail/Account/GroupAccount/Service.php
@@ -39,8 +39,6 @@ use Espo\Core\Mail\Account\StorageFactory;
 
 use Espo\Core\Utils\Crypt;
 
-use RecursiveIteratorIterator;
-
 class Service
 {
     private Fetcher $fetcher;
@@ -90,18 +88,7 @@ class Service
 
         $storage = $this->storageFactory->createWithParams($params);
 
-        $folderIterator = new RecursiveIteratorIterator(
-            $storage->getFolders(),
-            RecursiveIteratorIterator::SELF_FIRST
-        );
-
-        $list = [];
-
-        foreach ($folderIterator as $folder) {
-            $list[] = mb_convert_encoding($folder->getGlobalName(), 'UTF-8', 'UTF7-IMAP');
-        }
-
-        return $list;
+        return $storage->getFolderNames();
     }
 
     public function testConnection(Params $params): void
@@ -118,7 +105,7 @@ class Service
 
         $storage = $this->storageFactory->createWithParams($params);
 
-        $storage->getFolders();
+        $storage->getFolderNames();
     }
 
     /**
diff --git a/application/Espo/Core/Mail/Account/GroupAccount/StorageFactory.php b/application/Espo/Core/Mail/Account/GroupAccount/StorageFactory.php
index 5e951c5482..3f7c5e6bde 100644
--- a/application/Espo/Core/Mail/Account/GroupAccount/StorageFactory.php
+++ b/application/Espo/Core/Mail/Account/GroupAccount/StorageFactory.php
@@ -32,7 +32,7 @@ namespace Espo\Core\Mail\Account\GroupAccount;
 use Espo\Core\Mail\Account\Storage\Params;
 use Espo\Core\Mail\Account\Account;
 use Espo\Core\Mail\Account\StorageFactory as StorageFactoryInterface;
-
+use Espo\Core\Mail\Account\Storage\LaminasStorage;
 use Espo\Core\Mail\Mail\Storage\Imap;
 
 use Espo\Core\Utils\Crypt;
@@ -49,8 +49,6 @@ class StorageFactory implements StorageFactoryInterface
 
     private InjectableFactory $injectableFactory;
 
-    private string $storageClassName = Imap::class;
-
     public function __construct(Crypt $crypt, Log $log, InjectableFactory $injectableFactory)
     {
         $this->crypt = $crypt;
@@ -58,7 +56,7 @@ class StorageFactory implements StorageFactoryInterface
         $this->injectableFactory = $injectableFactory;
     }
 
-    public function create(Account $account): Imap
+    public function create(Account $account): LaminasStorage
     {
         $params = Params::createBuilder()
             ->setHost($account->getHost())
@@ -75,7 +73,7 @@ class StorageFactory implements StorageFactoryInterface
         return $this->createWithParams($params);
     }
 
-    public function createWithParams(Params $params): Imap
+    public function createWithParams(Params $params): LaminasStorage
     {
         $rawParams = [
             'host' => $params->getHost(),
@@ -127,6 +125,8 @@ class StorageFactory implements StorageFactoryInterface
             }
         }
 
-        return new $this->storageClassName($imapParams);
+        return new LaminasStorage(
+            new Imap($imapParams)
+        );
     }
 }
diff --git a/application/Espo/Core/Mail/Account/PersonalAccount/Service.php b/application/Espo/Core/Mail/Account/PersonalAccount/Service.php
index d002d4d85f..8b8f1a13b8 100644
--- a/application/Espo/Core/Mail/Account/PersonalAccount/Service.php
+++ b/application/Espo/Core/Mail/Account/PersonalAccount/Service.php
@@ -42,8 +42,6 @@ use Espo\Core\Utils\Crypt;
 
 use Espo\Entities\User;
 
-use RecursiveIteratorIterator;
-
 class Service
 {
     private Fetcher $fetcher;
@@ -107,18 +105,7 @@ class Service
 
         $storage = $this->storageFactory->createWithParams($params);
 
-        $folderIterator = new RecursiveIteratorIterator(
-            $storage->getFolders(),
-            RecursiveIteratorIterator::SELF_FIRST
-        );
-
-        $list = [];
-
-        foreach ($folderIterator as $folder) {
-            $list[] = mb_convert_encoding($folder->getGlobalName(), 'UTF-8', 'UTF7-IMAP');
-        }
-
-        return $list;
+        return $storage->getFolderNames();
     }
 
     public function testConnection(Params $params): void
@@ -156,7 +143,7 @@ class Service
 
         $storage = $this->storageFactory->createWithParams($params);
 
-        $storage->getFolders();
+        $storage->getFolderNames();
     }
 
     /**
diff --git a/application/Espo/Core/Mail/Account/PersonalAccount/StorageFactory.php b/application/Espo/Core/Mail/Account/PersonalAccount/StorageFactory.php
index 0d74c318e7..150609ce87 100644
--- a/application/Espo/Core/Mail/Account/PersonalAccount/StorageFactory.php
+++ b/application/Espo/Core/Mail/Account/PersonalAccount/StorageFactory.php
@@ -34,6 +34,7 @@ use Espo\Core\Mail\Account\StorageFactory as StorageFactoryInterface;
 use Espo\Core\Mail\Account\Account;
 
 use Espo\Core\Mail\Mail\Storage\Imap;
+use Espo\Core\Mail\Account\Storage\LaminasStorage;
 
 use Espo\Core\Utils\Crypt;
 use Espo\Core\Utils\Log;
@@ -56,8 +57,6 @@ class StorageFactory implements StorageFactoryInterface
 
     private EntityManager $entityManager;
 
-    private string $storageClassName = Imap::class;
-
     public function __construct(
         Crypt $crypt,
         Log $log,
@@ -70,7 +69,7 @@ class StorageFactory implements StorageFactoryInterface
         $this->entityManager = $entityManager;
     }
 
-    public function create(Account $account): Imap
+    public function create(Account $account): LaminasStorage
     {
         $params = Params::createBuilder()
             ->setHost($account->getHost())
@@ -89,7 +88,7 @@ class StorageFactory implements StorageFactoryInterface
         return $this->createWithParams($params);
     }
 
-    public function createWithParams(Params $params): Imap
+    public function createWithParams(Params $params): LaminasStorage
     {
         $rawParams = [
             'host' => $params->getHost(),
@@ -172,7 +171,9 @@ class StorageFactory implements StorageFactoryInterface
             }
         }
 
-        return new $this->storageClassName($imapParams);
+        return new LaminasStorage(
+            new Imap($imapParams)
+        );
     }
 
     private function getUserDataRepository(): UserDataRepository
diff --git a/application/Espo/Core/Mail/Account/Storage.php b/application/Espo/Core/Mail/Account/Storage.php
new file mode 100644
index 0000000000..562096da7d
--- /dev/null
+++ b/application/Espo/Core/Mail/Account/Storage.php
@@ -0,0 +1,98 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM - Open Source CRM application.
+ * Copyright (C) 2014-2021 Yurii Kuznietsov, Taras Machyshyn, Oleksii Avramenko
+ * Website: https://www.espocrm.com
+ *
+ * EspoCRM is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * EspoCRM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with EspoCRM. If not, see http://www.gnu.org/licenses/.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Mail\Account;
+
+use Espo\Core\Field\DateTime;
+
+interface Storage
+{
+    /**
+     * Set message flags.
+     *
+     * @param string[] $flags
+     */
+    public function setFlags(int $id, array $flags): void;
+
+    /**
+     * Get a message size.
+     */
+    public function getSize(int $id): int;
+
+    /**
+     * Get message raw content.
+     */
+    public function getRawContent(int $id): string;
+
+    /**
+     * Get a message unique ID.
+     */
+    public function getUniqueId(int $id): string;
+
+    /**
+     * Get IDs from unique ID.
+     *
+     * @return int[]
+     */
+    public function getIdsFromUniqueId(string $uniqueId): array;
+
+    /**
+     * Get IDs since a specific date.
+     *
+     * @return int[]
+     */
+    public function getIdsSinceDate(DateTime $since): array;
+
+    /**
+     * Get only header and flags. Won't fetch the whole email.
+     *
+     * @return array{header: string, flags: string[]}
+     */
+    public function getHeaderAndFlags(int $id): array;
+
+    /**
+     * Close the resource.
+     */
+    public function close(): void;
+
+    /**
+     * @retrun string[]
+     */
+    public function getFolderNames(): array;
+
+    /**
+     * Select a folder.
+     */
+    public function selectFolder(string $name): void;
+
+    /**
+     * Store a message.
+     */
+    public function appendMessage(string $content, ?string $folder = null): void;
+}
diff --git a/application/Espo/Core/Mail/Account/Storage/Flag.php b/application/Espo/Core/Mail/Account/Storage/Flag.php
new file mode 100644
index 0000000000..39f9a7217c
--- /dev/null
+++ b/application/Espo/Core/Mail/Account/Storage/Flag.php
@@ -0,0 +1,49 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM - Open Source CRM application.
+ * Copyright (C) 2014-2021 Yurii Kuznietsov, Taras Machyshyn, Oleksii Avramenko
+ * Website: https://www.espocrm.com
+ *
+ * EspoCRM is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * EspoCRM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with EspoCRM. If not, see http://www.gnu.org/licenses/.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Mail\Account\Storage;
+
+class Flag
+{
+    public const PASSED = 'Passed';
+
+    public const SEEN = '\Seen';
+
+    public const UNSEEN = '\Unseen';
+
+    public const ANSWERED = '\Answered';
+
+    public const FLAGGED = '\Flagged';
+
+    public const DELETED = '\Deleted';
+
+    public const DRAFT = '\Draft';
+
+    public const RECENT = '\Recent';
+}
diff --git a/application/Espo/Core/Mail/Account/Storage/LaminasStorage.php b/application/Espo/Core/Mail/Account/Storage/LaminasStorage.php
new file mode 100644
index 0000000000..ec8a404b9a
--- /dev/null
+++ b/application/Espo/Core/Mail/Account/Storage/LaminasStorage.php
@@ -0,0 +1,131 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM - Open Source CRM application.
+ * Copyright (C) 2014-2021 Yurii Kuznietsov, Taras Machyshyn, Oleksii Avramenko
+ * Website: https://www.espocrm.com
+ *
+ * EspoCRM is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * EspoCRM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with EspoCRM. If not, see http://www.gnu.org/licenses/.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Mail\Account\Storage;
+
+use Espo\Core\Mail\Account\Storage;
+use Espo\Core\Mail\Mail\Storage\Imap;
+use Espo\Core\Field\DateTime;
+
+use RecursiveIteratorIterator;
+
+class LaminasStorage implements Storage
+{
+    private Imap $imap;
+
+    public function __construct(Imap $imap)
+    {
+        $this->imap = $imap;
+    }
+
+    /**
+     * @param string[] $flags
+     */
+    public function setFlags(int $id, array $flags): void
+    {
+        $this->imap->setFlags($id, $flags);
+    }
+
+    public function getSize(int $id): int
+    {
+        return $this->imap->getSize($id);
+    }
+
+    public function getRawContent(int $id): string
+    {
+        return $this->imap->getRawContent($id);
+    }
+
+    public function getUniqueId(int $id): string
+    {
+        return $this->imap->getUniqueId($id);
+    }
+
+    /**
+     * @return int[]
+     */
+    public function getIdsFromUniqueId(string $uniqueId): array
+    {
+        return $this->imap->getIdsFromUniqueId($uniqueId);
+    }
+
+    /**
+     * @return int[]
+     */
+    public function getIdsSinceDate(DateTime $since): array
+    {
+        return $this->imap->getIdsSinceDate(
+            $since->getDateTime()->format('d-M-Y')
+        );
+    }
+
+    /**
+     * @return array{header: string, flags: string[]}
+     */
+    public function getHeaderAndFlags(int $id): array
+    {
+        return $this->imap->getHeaderAndFlags($id);
+    }
+
+    public function close(): void
+    {
+        $this->imap->close();
+    }
+
+    /**
+     * @retrun string[]
+     */
+    public function getFolderNames(): array
+    {
+        $folderIterator = new RecursiveIteratorIterator(
+            $this->imap->getFolders(),
+            RecursiveIteratorIterator::SELF_FIRST
+        );
+
+        $list = [];
+
+        foreach ($folderIterator as $folder) {
+            $list[] = mb_convert_encoding($folder->getGlobalName(), 'UTF-8', 'UTF7-IMAP');
+        }
+
+        return $list;
+    }
+
+    public function selectFolder(string $name): void
+    {
+        $nameConverted = mb_convert_encoding($name, 'UTF7-IMAP', 'UTF-8');
+
+        $this->imap->selectFolder($nameConverted);
+    }
+
+    public function appendMessage(string $content, ?string $folder = null): void
+    {
+        $this->imap->appendMessage($content, $folder);
+    }
+}
diff --git a/application/Espo/Core/Mail/Account/StorageFactory.php b/application/Espo/Core/Mail/Account/StorageFactory.php
index 8ebcce00f8..7305425885 100644
--- a/application/Espo/Core/Mail/Account/StorageFactory.php
+++ b/application/Espo/Core/Mail/Account/StorageFactory.php
@@ -29,12 +29,12 @@
 
 namespace Espo\Core\Mail\Account;
 
-use Espo\Core\Mail\Mail\Storage\Imap;
 use Espo\Core\Mail\Account\Storage\Params;
+use Espo\Core\Mail\Account\Storage;
 
 interface StorageFactory
 {
-    public function create(Account $account): Imap;
+    public function create(Account $account): Storage;
 
-    public function createWithParams(Params $params): Imap;
+    public function createWithParams(Params $params): Storage;
 }
diff --git a/application/Espo/Core/Mail/Importer.php b/application/Espo/Core/Mail/Importer.php
index 40e1566e12..4823772ec3 100644
--- a/application/Espo/Core/Mail/Importer.php
+++ b/application/Espo/Core/Mail/Importer.php
@@ -102,7 +102,9 @@ class Importer
         $folderData = $data->getFolderData();
 
         $parser = $message instanceof MessageWrapper ?
-            $message->getParser() :
+            (
+                $message->getParser() ?? $this->parserFactory->create()
+            ) :
             $this->parserFactory->create();
 
         /** @var Email $email */
diff --git a/application/Espo/Core/Mail/Mail/Storage/Imap.php b/application/Espo/Core/Mail/Mail/Storage/Imap.php
index 1d2c984036..344e69c257 100644
--- a/application/Espo/Core/Mail/Mail/Storage/Imap.php
+++ b/application/Espo/Core/Mail/Mail/Storage/Imap.php
@@ -31,31 +31,43 @@ namespace Espo\Core\Mail\Mail\Storage;
 
 class Imap extends \Laminas\Mail\Storage\Imap
 {
-    public function getIdsFromUID($uid)
+    /**
+     * @return int[]
+     */
+    public function getIdsFromUniqueId(string $uid): array
     {
-        $uid = intval($uid) + 1;
-        return $this->protocol->search(['UID ' . $uid . ':*']);
+        $nextUid = strval(intval($uid) + 1);
+
+        return $this->protocol->search(['UID ' . $nextUid . ':*']);
     }
 
-    public function getIdsFromDate($date)
+    /**
+     * @return int[]
+     */
+    public function getIdsSinceDate(string $date): array
     {
         return $this->protocol->search(['SINCE "' . $date . '"']);
     }
 
-    public function getHeaderAndFlags($id, $part = null)
+    /**
+     * @param int $id
+     * @return array{header: string, flags: string[]}
+     */
+    public function getHeaderAndFlags(int $id): array
     {
         $data = $this->protocol->fetch(['FLAGS', 'RFC822.HEADER'], $id);
 
         $header = $data['RFC822.HEADER'];
 
         $flags = [];
+
         foreach ($data['FLAGS'] as $flag) {
             $flags[] = isset(static::$knownFlags[$flag]) ? static::$knownFlags[$flag] : $flag;
         }
 
         return [
             'flags' => $flags,
-            'header' => $header
+            'header' => $header,
         ];
     }
 }
diff --git a/application/Espo/Core/Mail/Message.php b/application/Espo/Core/Mail/Message.php
index 42f0752943..5e4162ac39 100644
--- a/application/Espo/Core/Mail/Message.php
+++ b/application/Espo/Core/Mail/Message.php
@@ -56,11 +56,6 @@ interface Message
      */
     public function getFullRawContent(): string;
 
-    /**
-     * Set a full raw message.
-     */
-    public function setFullRawContent(string $content): void;
-
     /**
      * Get flags.
      *
diff --git a/application/Espo/Core/Mail/MessageWrapper.php b/application/Espo/Core/Mail/MessageWrapper.php
index aabdc27550..b788fff3f6 100644
--- a/application/Espo/Core/Mail/MessageWrapper.php
+++ b/application/Espo/Core/Mail/MessageWrapper.php
@@ -29,16 +29,16 @@
 
 namespace Espo\Core\Mail;
 
-use Espo\Core\Mail\Mail\Storage\Imap;
+use Espo\Core\Mail\Account\Storage;
 
 class MessageWrapper implements Message
 {
+    private int $id;
+
     private $parser;
 
     private $storage;
 
-    private $id;
-
     private $rawHeader = null;
 
     private $rawContent = null;
@@ -47,8 +47,12 @@ class MessageWrapper implements Message
 
     private $flagList = null;
 
-    public function __construct(?Imap $storage = null, ?string $id = null, ?Parser $parser = null)
-    {
+    public function __construct(
+        int $id,
+        ?Storage $storage = null,
+        ?Parser $parser = null,
+        ?string $fullRawContent = null
+    ) {
         if ($storage) {
             $data = $storage->getHeaderAndFlags($id);
 
@@ -59,11 +63,7 @@ class MessageWrapper implements Message
         $this->id = $id;
         $this->storage = $storage;
         $this->parser = $parser;
-    }
-
-    public function setFullRawContent(string $content): void
-    {
-        $this->fullRawContent = $content;
+        $this->fullRawContent = $fullRawContent;
     }
 
     public function getRawHeader(): string
@@ -89,7 +89,7 @@ class MessageWrapper implements Message
     public function getRawContent(): string
     {
         if (is_null($this->rawContent)) {
-            $this->rawContent = $this->storage->getRawContent((int) $this->id);
+            $this->rawContent = $this->storage->getRawContent($this->id);
         }
 
         return $this->rawContent ?? '';
diff --git a/tests/unit/Espo/Core/Mail/ImporterDataTest.php b/tests/unit/Espo/Core/Mail/ImporterDataTest.php
index 037b2f66d6..142aa5d87c 100644
--- a/tests/unit/Espo/Core/Mail/ImporterDataTest.php
+++ b/tests/unit/Espo/Core/Mail/ImporterDataTest.php
@@ -29,13 +29,10 @@
 
 namespace tests\unit\Espo\Core\Mail;
 
-use Espo\Core\{
-    Mail\ImporterData,
-};
+use Espo\Core\Mail\Importer\Data as ImporterData;
 
 use Espo\Entities\EmailFilter;
 
-
 class ImporterDataTest extends \PHPUnit\Framework\TestCase
 {
 
diff --git a/tests/unit/Espo/Core/Mail/ImporterTest.php b/tests/unit/Espo/Core/Mail/ImporterTest.php
index b67fe8e1f5..e3152b34ea 100644
--- a/tests/unit/Espo/Core/Mail/ImporterTest.php
+++ b/tests/unit/Espo/Core/Mail/ImporterTest.php
@@ -165,9 +165,7 @@ class ImporterTest extends \PHPUnit\Framework\TestCase
             $this->linkMultipleSaver
         );
 
-        $message = new MessageWrapper();
-
-        $message->setFullRawContent($contents);
+        $message = new MessageWrapper(0, null, null, $contents);
 
         $data = ImporterData
             ::create()