TF-389 Fix can not see the attachment in EmailView

model/lib/email/attachment.dart

@@ -27,7 +27,9 @@ class Attachment with EquatableMixin {
     this.disposition,
   });
 
-  bool cidNotEmpty() => cid != null && cid!.isNotEmpty;
+  bool noCid() => cid == null || cid?.isEmpty == true;
+
+  bool hasCid() => cid != null && cid?.isNotEmpty == true;
 
   String getDownloadUrl(String baseDownloadUrl, AccountId accountId) {
     final downloadUriTemplate = UriTemplate('$baseDownloadUrl');

model/lib/extensions/list_attachment_extension.dart

@@ -12,12 +12,13 @@ extension ListAttachmentExtension on List<Attachment> {
     return totalSize;
   }
 
-  List<Attachment> get attachmentsWithDispositionAttachment {
-    return where((attachment) => attachment.disposition == ContentDisposition.attachment).toList();
+  List<Attachment> get listAttachmentsDisplayedOutSide {
+    return where((attachment) => attachment.disposition == ContentDisposition.attachment || attachment.noCid())
+        .toList();
   }
 
-  List<Attachment> get attachmentWithDispositionInlines {
-    return where((attachment) => attachment.disposition == ContentDisposition.inline && attachment.cidNotEmpty())
+  List<Attachment> get listAttachmentsDisplayedInContent {
+    return where((attachment) => attachment.hasCid())
       .toList();
   }
 }