diff --git a/lib/filter-handler.js b/lib/filter-handler.js
index da06d39..383cc95 100644
--- a/lib/filter-handler.js
+++ b/lib/filter-handler.js
@@ -466,9 +466,13 @@ class FilterHandler {
 
                                 if (filterActions.get('delete')) {
                                     // nothing to do with the message, just continue
+                                    let err = new Error('Message dropped by policy');
+                                    err.code = 'DroppedByPolicy';
+
                                     return callback(null, {
                                         userData,
-                                        response: 'Message dropped by policy as ' + prepared.id.toString()
+                                        response: 'Message dropped by policy as ' + prepared.id.toString(),
+                                        error: err
                                     });
                                 }
 
@@ -544,7 +548,8 @@ class FilterHandler {
                                             null,
                                             {
                                                 userData,
-                                                response: err ? err : 'Message stored as ' + info.id.toString()
+                                                response: err ? err : 'Message stored as ' + info.id.toString(),
+                                                error: err
                                             },
                                             !isEncrypted
                                                 ? {
diff --git a/package.json b/package.json
index a490582..9a9bc65 100644
--- a/package.json
+++ b/package.json
@@ -8,10 +8,7 @@
         "test": "mongo --eval 'db.dropDatabase()' wildduck-test && redis-cli -n 13 flushdb && NODE_ENV=test grunt",
         "apidoc": "apidoc -i lib/api/ -o docs/"
     },
-    "keywords": [
-        "imap",
-        "mail server"
-    ],
+    "keywords": ["imap", "mail server"],
     "author": "Andris Reinman",
     "license": "EUPL-1.1",
     "devDependencies": {
@@ -53,7 +50,7 @@
         "mobileconfig": "2.1.0",
         "mongo-cursor-pagination-node6": "5.0.0",
         "mongodb": "3.0.0-rc0",
-        "mongodb-extended-json": "^1.10.0",
+        "mongodb-extended-json": "1.10.0",
         "nodemailer": "4.4.1",
         "npmlog": "4.1.2",
         "openpgp": "2.6.0",