diff --git a/dev/Stores/User/Folder.js b/dev/Stores/User/Folder.js
index 35a665c67..874b54572 100644
--- a/dev/Stores/User/Folder.js
+++ b/dev/Stores/User/Folder.js
@@ -24,23 +24,22 @@ ignoredKeywords = [
 	// Mailo
 	'sent',
 	// KMail
-	'$attachment',
 	'$encrypted',
 	'$error',
 	'$ignored',
 	'$invitation',
 	'$queued',
-	'$replied',
 	'$sent',
 	'$signed',
 	'$todo',
 	'$watched',
 	// GMail
-	'$replied',
-	'$attachment',
 	'$notphishing',
 	'junk',
 	'nonjunk',
+	// KMail & GMail
+	'$attachment',
+	'$replied',
 	// Others
 	'$readreceipt'
 ],
diff --git a/dev/View/User/MailBox/MessageView.js b/dev/View/User/MailBox/MessageView.js
index b17b0b98f..6454758b4 100644
--- a/dev/View/User/MailBox/MessageView.js
+++ b/dev/View/User/MailBox/MessageView.js
@@ -36,7 +36,7 @@ import { MessageFlagsCache } from 'Common/Cache';
 import { AppUserStore } from 'Stores/User/App';
 import { SettingsUserStore } from 'Stores/User/Settings';
 import { AccountUserStore } from 'Stores/User/Account';
-import { FolderUserStore } from 'Stores/User/Folder';
+import { FolderUserStore, isAllowedKeyword } from 'Stores/User/Folder';
 import { MessageUserStore } from 'Stores/User/Message';
 import { MessagelistUserStore } from 'Stores/User/Messagelist';
 import { ThemeStore } from 'Stores/Theme';
@@ -529,8 +529,8 @@ export class MailMessageView extends AbstractViewRight {
 	newTag() {
 		let message = currentMessage();
 		if (message) {
-			let keyword = prompt(i18n('MESSAGE/NEW_TAG'), '')?.replace(/\s+/g, '');
-			if (keyword.length) {
+			let keyword = prompt(i18n('MESSAGE/NEW_TAG'), '')?.replace(/[\s\\]+/g, '');
+			if (keyword.length && isAllowedKeyword(keyword)) {
 				message.toggleTag(keyword);
 				FolderUserStore.currentFolder().permanentFlags.push(keyword);
 			}
diff --git a/snappymail/v/0.0.0/app/libraries/MailSo/Mail/Message.php b/snappymail/v/0.0.0/app/libraries/MailSo/Mail/Message.php
index e7c9f83b3..183d90d3e 100644
--- a/snappymail/v/0.0.0/app/libraries/MailSo/Mail/Message.php
+++ b/snappymail/v/0.0.0/app/libraries/MailSo/Mail/Message.php
@@ -647,6 +647,15 @@ class Message implements \JsonSerializable
 			$this->aFlagsLowerCase
 		), true);
 */
+		// https://datatracker.ietf.org/doc/html/rfc5788#section-3.4.1
+		// Thunderbird $label1 is same as $Important?
+		// Thunderbird $label4 is same as $todo?
+		$aFlags = \array_unique(\str_replace(
+			['$readreceipt', '$replied',  /* 'junk',  'nonjunk',  '$queued',        '$sent',      'sent'*/],
+			['$mdnsent',     '\\answered',/* '$junk', '$notjunk', '$submitpending', '$submitted', '$submitted'*/],
+			$this->aFlagsLowerCase
+		));
+
 		return array(
 			'@Object' => 'Object/Message',
 			'Folder' => $this->sFolder,
@@ -676,7 +685,7 @@ class Message implements \JsonSerializable
 
 			'Attachments' => $this->oAttachments ? $this->oAttachments->SpecData() : null,
 
-			'Flags' => $this->aFlagsLowerCase,
+			'Flags' => $aFlags,
 
 			// https://datatracker.ietf.org/doc/html/rfc8621#section-4.1.1
 			'id' => $this->sEmailId,
diff --git a/snappymail/v/0.0.0/app/libraries/RainLoop/Actions/Response.php b/snappymail/v/0.0.0/app/libraries/RainLoop/Actions/Response.php
index 9900f7dab..e2aa0e3ba 100644
--- a/snappymail/v/0.0.0/app/libraries/RainLoop/Actions/Response.php
+++ b/snappymail/v/0.0.0/app/libraries/RainLoop/Actions/Response.php
@@ -194,19 +194,6 @@ trait Response
 				'FileName' => (\strlen($sSubject) ? \MailSo\Base\Utils::ClearXss($sSubject) : 'message-'.$mResult['Uid']) . '.eml'
 			));
 
-			// https://datatracker.ietf.org/doc/html/rfc5788#section-3.4.1
-			$key = \array_search('$readreceipt', $mResult['Flags']);
-			if (false !== $key) {
-				$mResult['Flags'][$key] = '$mdnsent';
-			}
-			// KMail
-			$key = \array_search('$replied', $mResult['Flags']);
-			if (false !== $key) {
-				$mResult['Flags'][$key] = '\\answered';
-			}
-
-			$mResult['Flags'] = \array_unique($mResult['Flags']);
-
 			if ('Message' === $sParent)
 			{
 				$mResult['DraftInfo'] = $mResponse->DraftInfo();