diff --git a/index.js b/index.js
index 9c0910d..409da68 100644
--- a/index.js
+++ b/index.js
@@ -1413,7 +1413,8 @@ exports.hook_queue = function (next, connection) {
                             _attachment_disposition: attachment.disposition,
                             _attachment_size: attachment.size,
                             _attachment_encoding: attachment.transferEncoding,
-                            _attachment_count: response.attachments.length
+                            _attachment_count: response.attachments.length,
+                            _attachment_sha256: attachment.fileContentHash
                         });
                     });
                 }