Add model for mailbox & mail

model/lib/mail/presentation_mail.dart

@@ -0,0 +1,17 @@
+
+import 'package:equatable/equatable.dart';
+
+class PresentationMail with EquatableMixin {
+
+  final String id;
+  final String? message;
+
+  PresentationMail(this.id, {this.message});
+
+  factory PresentationMail.createMailEmpty() {
+    return PresentationMail('empty');
+  }
+
+  @override
+  List<Object?> get props => [id, message];
+}

model/lib/mailbox/presentation_mailbox.dart

@@ -1,4 +1,5 @@
 import 'package:equatable/equatable.dart';
+import 'package:jmap_dart_client/jmap/core/id.dart';
 import 'package:jmap_dart_client/jmap/mail/mailbox/mailbox.dart';
 import 'package:jmap_dart_client/jmap/mail/mailbox/mailbox_rights.dart';
 import 'package:model/mailbox/select_mode.dart';
@@ -35,6 +36,10 @@ class PresentationMailbox with EquatableMixin {
     }
   );
 
+  factory PresentationMailbox.createMailboxEmpty() {
+    return PresentationMailbox(MailboxId(Id("empty")));
+  }
+
   bool hasParentId() => parentId != null && parentId!.id.value.isNotEmpty;
 
   bool hasRole() => role != null && role!.value.isNotEmpty;

model/lib/model.dart

@@ -7,7 +7,11 @@ export 'account/password.dart';
 // User
 export 'user/user_id.dart';
 export 'user/user.dart';
+
 // Mailbox
 export 'mailbox/presentation_mailbox.dart';
 export 'mailbox/select_mode.dart';
 export 'mailbox/expand_mode.dart';
+
+// Mail
+export 'mail/presentation_mail.dart';