diff --git a/lib/features/thread/data/extensions/email_cache_extension.dart b/lib/features/thread/data/extensions/email_cache_extension.dart
index 914f57612a..5d101f04ab 100644
--- a/lib/features/thread/data/extensions/email_cache_extension.dart
+++ b/lib/features/thread/data/extensions/email_cache_extension.dart
@@ -4,6 +4,7 @@ import 'package:jmap_dart_client/jmap/core/id.dart';
 import 'package:jmap_dart_client/jmap/core/unsigned_int.dart';
 import 'package:jmap_dart_client/jmap/core/utc_date.dart';
 import 'package:jmap_dart_client/jmap/mail/email/email.dart';
+import 'package:jmap_dart_client/jmap/mail/email/individual_header_identifier.dart';
 import 'package:jmap_dart_client/jmap/mail/email/keyword_identifier.dart';
 import 'package:jmap_dart_client/jmap/mail/mailbox/mailbox.dart';
 import 'package:tmail_ui_user/features/cleanup/domain/model/email_cleanup_rule.dart';
@@ -31,6 +32,9 @@ extension EmailCacheExtension on EmailCache {
       mailboxIds: mailboxIds != null
         ? Map.fromIterables(mailboxIds!.keys.map((value) => MailboxId(Id(value))), mailboxIds!.values)
         : null,
+      headerCalendarEvent: headerCalendarEvent != null
+        ? Map.fromIterables(headerCalendarEvent!.keys.map((value) => IndividualHeaderIdentifier(value)), headerCalendarEvent!.values)
+        : null
     );
   }
 
diff --git a/lib/features/thread/data/extensions/email_extension.dart b/lib/features/thread/data/extensions/email_extension.dart
index 037e9182d7..d6a02dd60d 100644
--- a/lib/features/thread/data/extensions/email_extension.dart
+++ b/lib/features/thread/data/extensions/email_extension.dart
@@ -1,5 +1,6 @@
 import 'package:jmap_dart_client/jmap/mail/email/email.dart';
 import 'package:jmap_dart_client/jmap/mail/mailbox/mailbox.dart';
+import 'package:tmail_ui_user/features/thread/data/extensions/map_header_identifier_id_extension.dart';
 import 'package:tmail_ui_user/features/thread/data/model/email_cache.dart';
 import 'package:tmail_ui_user/features/thread/data/extensions/map_keywords_extension.dart';
 import 'package:tmail_ui_user/features/thread/data/extensions/email_address_extension.dart';
@@ -23,6 +24,7 @@ extension EmailExtension on Email {
       bcc: bcc?.map((emailAddress) => emailAddress.toEmailAddressHiveCache()).toList(),
       replyTo: replyTo?.map((emailAddress) => emailAddress.toEmailAddressHiveCache()).toList(),
       mailboxIds: mailboxIds?.toMapString(),
+      headerCalendarEvent: headerCalendarEvent?.toMapString(),
     );
   }
 
diff --git a/lib/features/thread/data/extensions/map_header_identifier_id_extension.dart b/lib/features/thread/data/extensions/map_header_identifier_id_extension.dart
new file mode 100644
index 0000000000..081749cc40
--- /dev/null
+++ b/lib/features/thread/data/extensions/map_header_identifier_id_extension.dart
@@ -0,0 +1,7 @@
+
+import 'package:jmap_dart_client/jmap/mail/email/individual_header_identifier.dart';
+
+extension MapHeaderIdentifierExtension on Map<IndividualHeaderIdentifier, String?> {
+
+  Map<String, String?> toMapString() => Map.fromIterables(keys.map((identifier) => identifier.value), values);
+}
\ No newline at end of file
diff --git a/lib/features/thread/data/model/email_cache.dart b/lib/features/thread/data/model/email_cache.dart
index a407d5125c..6db80e1d50 100644
--- a/lib/features/thread/data/model/email_cache.dart
+++ b/lib/features/thread/data/model/email_cache.dart
@@ -51,6 +51,9 @@ class EmailCache extends HiveObject with EquatableMixin {
   @HiveField(13)
   Map<String, bool>? mailboxIds;
 
+  @HiveField(14)
+  Map<String, String?>? headerCalendarEvent;
+
   EmailCache(
     this.id,
     {
@@ -67,6 +70,7 @@ class EmailCache extends HiveObject with EquatableMixin {
       this.bcc,
       this.replyTo,
       this.mailboxIds,
+      this.headerCalendarEvent,
     }
   );
 
@@ -86,5 +90,6 @@ class EmailCache extends HiveObject with EquatableMixin {
     preview,
     hasAttachment,
     mailboxIds,
+    headerCalendarEvent,
   ];
 }
\ No newline at end of file
diff --git a/model/lib/extensions/email_extension.dart b/model/lib/extensions/email_extension.dart
index 63d57e8e8a..e6b4f119b8 100644
--- a/model/lib/extensions/email_extension.dart
+++ b/model/lib/extensions/email_extension.dart
@@ -4,6 +4,7 @@ import 'dart:convert';
 import 'package:jmap_dart_client/jmap/core/properties/properties.dart';
 import 'package:jmap_dart_client/jmap/mail/email/email.dart';
 import 'package:jmap_dart_client/jmap/mail/email/email_body_part.dart';
+import 'package:jmap_dart_client/jmap/mail/email/individual_header_identifier.dart';
 import 'package:jmap_dart_client/jmap/mail/email/keyword_identifier.dart';
 import 'package:jmap_dart_client/jmap/mail/mailbox/mailbox.dart';
 import 'package:model/model.dart';
@@ -38,24 +39,25 @@ extension EmailExtension on Email {
 
   Email updatedEmail({Map<KeyWordIdentifier, bool>? newKeywords, Map<MailboxId, bool>? newMailboxIds}) {
     return Email(
-        id: id,
-        keywords: newKeywords ?? keywords,
-        size: size,
-        receivedAt: receivedAt,
-        hasAttachment: hasAttachment,
-        preview: preview,
-        subject: subject,
-        sentAt: sentAt,
-        from: from,
-        to: to,
-        cc: cc,
-        bcc: bcc,
-        replyTo: replyTo,
-        mailboxIds: newMailboxIds ?? mailboxIds,
-        htmlBody: htmlBody,
-        bodyValues: bodyValues,
-        headerUserAgent: headerUserAgent,
-        attachments: attachments
+      id: id,
+      keywords: newKeywords ?? keywords,
+      size: size,
+      receivedAt: receivedAt,
+      hasAttachment: hasAttachment,
+      preview: preview,
+      subject: subject,
+      sentAt: sentAt,
+      from: from,
+      to: to,
+      cc: cc,
+      bcc: bcc,
+      replyTo: replyTo,
+      mailboxIds: newMailboxIds ?? mailboxIds,
+      htmlBody: htmlBody,
+      bodyValues: bodyValues,
+      headerUserAgent: headerUserAgent,
+      attachments: attachments,
+      headerCalendarEvent: headerCalendarEvent
     );
   }
 
@@ -97,6 +99,7 @@ extension EmailExtension on Email {
       bcc: updatedProperties.contain(EmailProperty.bcc) ? newEmail.bcc : bcc,
       replyTo: updatedProperties.contain(EmailProperty.replyTo) ? newEmail.replyTo : replyTo,
       mailboxIds: updatedProperties.contain(EmailProperty.mailboxIds) ? newEmail.mailboxIds : mailboxIds,
+      headerCalendarEvent: updatedProperties.contain(IndividualHeaderIdentifier.headerCalendarEvent.value) ? newEmail.headerCalendarEvent : headerCalendarEvent,
     );
   }
 
diff --git a/model/lib/extensions/presentation_email_extension.dart b/model/lib/extensions/presentation_email_extension.dart
index aa57db66f2..24c6b9f973 100644
--- a/model/lib/extensions/presentation_email_extension.dart
+++ b/model/lib/extensions/presentation_email_extension.dart
@@ -97,6 +97,9 @@ extension PresentationEmailExtension on PresentationEmail {
       replyTo: replyTo,
       htmlBody: htmlBody,
       bodyValues: bodyValues,
+      mailboxIds: mailboxIds,
+      headers: emailHeader?.toSet(),
+      headerCalendarEvent: headerCalendarEvent
     );
   }