diff --git a/mailpoet/assets/js/src/email-editor/engine/store/actions.ts b/mailpoet/assets/js/src/email-editor/engine/store/actions.ts
index 79811bb74b..1b3ede5772 100644
--- a/mailpoet/assets/js/src/email-editor/engine/store/actions.ts
+++ b/mailpoet/assets/js/src/email-editor/engine/store/actions.ts
@@ -6,7 +6,7 @@ import { store as noticesStore } from '@wordpress/notices';
 import { __ } from '@wordpress/i18n';
 import { apiFetch } from '@wordpress/data-controls';
 import { storeName, mainSidebarEmailTab } from './constants';
-import { SendingPreviewStatus, State, Feature } from './types';
+import { SendingPreviewStatus, State, Feature, EmailStyles } from './types';
 
 export const toggleFeature =
   (feature: Feature) =>
@@ -124,6 +124,30 @@ export function* updateEmailMailPoetProperty(name: string, value: string) {
   );
 }
 
+export function* updateEmailMailPoetTheme(theme: EmailStyles) {
+  const postId = select(storeName).getEmailPostId();
+  // There can be a better way how to get the edited post data
+  const editedPost = select(coreDataStore).getEditedEntityRecord(
+    'postType',
+    'mailpoet_email',
+    postId,
+  );
+  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+  // @ts-ignore
+  const mailpoetData = editedPost?.mailpoet_data || {};
+  yield dispatch(coreDataStore).editEntityRecord(
+    'postType',
+    'mailpoet_email',
+    postId,
+    {
+      mailpoet_data: {
+        ...mailpoetData,
+        theme,
+      },
+    },
+  );
+}
+
 export function* requestSendingNewsletterPreview(
   newsletterId: number,
   email: string,
diff --git a/mailpoet/lib/EmailEditor/Engine/EmailEditor.php b/mailpoet/lib/EmailEditor/Engine/EmailEditor.php
index 25b6ec98ca..e601658626 100644
--- a/mailpoet/lib/EmailEditor/Engine/EmailEditor.php
+++ b/mailpoet/lib/EmailEditor/Engine/EmailEditor.php
@@ -5,7 +5,7 @@ namespace MailPoet\EmailEditor\Engine;
 use MailPoet\Entities\NewsletterEntity;
 
 /**
- * @phpstan-type EmailPostType array{name: string, args: array}
+ * @phpstan-type EmailPostType array{name: string, args: array, meta: array{key: string, args: array}[]}
  * See register_post_type for details about EmailPostType args.
  */
 class EmailEditor {
@@ -35,6 +35,13 @@ class EmailEditor {
         $postType['name'],
         array_merge($this->getDefaultEmailPostArgs(), $postType['args'])
       );
+      foreach ($postType['meta'] as $postMeta) {
+        register_post_meta(
+          $postType['name'],
+          $postMeta['key'],
+          $postMeta['args']
+        );
+      }
     }
   }
 
diff --git a/mailpoet/lib/EmailEditor/Integrations/MailPoet/EmailApiController.php b/mailpoet/lib/EmailEditor/Integrations/MailPoet/EmailApiController.php
index 081d0a765c..a4be82475a 100644
--- a/mailpoet/lib/EmailEditor/Integrations/MailPoet/EmailApiController.php
+++ b/mailpoet/lib/EmailEditor/Integrations/MailPoet/EmailApiController.php
@@ -34,6 +34,7 @@ class EmailApiController {
       'subject' => $newsletter ? $newsletter->getSubject() : '',
       'preheader' => $newsletter ? $newsletter->getPreheader() : '',
       'preview_url' => $this->newsletterUrl->getViewInBrowserUrl($newsletter),
+      'theme' => get_post_meta($postEmailData['id'], EmailEditor::MAILPOET_EMAIL_META_THEME_TYPE, true),
     ];
   }
 
@@ -49,6 +50,8 @@ class EmailApiController {
       throw new UnexpectedValueException('Newsletter ID does not match the post ID');
     }
 
+    update_post_meta($emailPost->ID, EmailEditor::MAILPOET_EMAIL_META_THEME_TYPE, $data['theme']);
+
     $newsletter->setSubject($data['subject']);
     $newsletter->setPreheader($data['preheader']);
     $this->newsletterRepository->flush();
@@ -60,6 +63,7 @@ class EmailApiController {
       'subject' => Builder::string(),
       'preheader' => Builder::string(),
       'preview_url' => Builder::string(),
+      'theme' => Builder::object(),
     ])->toArray();
   }
 }
diff --git a/mailpoet/lib/EmailEditor/Integrations/MailPoet/EmailEditor.php b/mailpoet/lib/EmailEditor/Integrations/MailPoet/EmailEditor.php
index 014f2330ac..0e93dcdbd4 100644
--- a/mailpoet/lib/EmailEditor/Integrations/MailPoet/EmailEditor.php
+++ b/mailpoet/lib/EmailEditor/Integrations/MailPoet/EmailEditor.php
@@ -5,9 +5,12 @@ namespace MailPoet\EmailEditor\Integrations\MailPoet;
 use MailPoet\Features\FeaturesController;
 use MailPoet\Util\CdnAssetUrl;
 use MailPoet\WP\Functions as WPFunctions;
+use WP_Post;
+use WP_Theme_JSON;
 
 class EmailEditor {
   const MAILPOET_EMAIL_POST_TYPE = 'mailpoet_email';
+  const MAILPOET_EMAIL_META_THEME_TYPE = 'mailpoet_email_theme';
 
   /** @var WPFunctions */
   private $wp;
@@ -38,6 +41,7 @@ class EmailEditor {
       return;
     }
     $this->wp->addFilter('mailpoet_email_editor_post_types', [$this, 'addEmailPostType']);
+    $this->wp->addFilter('mailpoet_email_editor_rendering_theme_styles', [$this, 'extendEmailThemeStyles'], 10, 2);
     $this->extendEmailPostApi();
   }
 
@@ -51,6 +55,17 @@ class EmailEditor {
         ],
         'rewrite' => ['slug' => self::MAILPOET_EMAIL_POST_TYPE],
       ],
+      'meta' => [
+        [
+          'key' => self::MAILPOET_EMAIL_META_THEME_TYPE,
+          'args' => [
+            'show_in_rest' => true,
+            'single' => true,
+            'type' => 'object',
+            'default' => ['version' => 2],
+          ],
+        ],
+      ],
     ];
     return $postTypes;
   }
@@ -85,4 +100,12 @@ class EmailEditor {
       <!-- /wp:paragraph -->
     ';
   }
+
+  public function extendEmailThemeStyles(WP_Theme_JSON $theme, WP_Post $post): WP_Theme_JSON {
+    $emailTheme = get_post_meta($post->ID, self::MAILPOET_EMAIL_META_THEME_TYPE, true);
+    if ($emailTheme && is_array($emailTheme)) {
+      $theme->merge(new WP_Theme_JSON($emailTheme));
+    }
+    return $theme;
+  }
 }