return-path added in email object

objects/email/definition.json

@@ -3,7 +3,7 @@
   "uuid": "a0c666e0-fc65-4be8-b48f-3423d788b552",
   "meta-category": "network",
   "description": "Email object describing an email with meta-information",
-  "version": 4,
+  "version": 5,
   "attributes": {
     "reply-to": {
       "description": "Email address the reply will be sent to",
@@ -106,6 +106,14 @@
         "Payload delivery"
       ]
     },
+    "return-path": {
+      "description": "Message return path",
+      "misp-attribute": "text",
+      "ui-priority": 1,
+      "categories": [
+        "Payload delivery"
+      ]
+    },
     "from-display-name": {
       "description": "Display name of the sender",
       "misp-attribute": "email-src-display-name",
@@ -129,6 +137,7 @@
     "mime-boundary",
     "thread-index",
     "header",
-    "x-mailer"
+    "x-mailer",
+    "return-path"
   ]
 }