diff --git a/packages/nylas-core/imap-connection.js b/packages/nylas-core/imap-connection.js
index 8da026230..96e3df2f7 100644
--- a/packages/nylas-core/imap-connection.js
+++ b/packages/nylas-core/imap-connection.js
@@ -73,21 +73,21 @@ class IMAPBox {
     })
   }
 
-  fetchStream({messageId, options}) {
-    if (!messageId) {
-      throw new Error("IMAPConnection.fetchStream requires a message identifier.")
+  fetchStream({uid, options}) {
+    if (!uid) {
+      throw new Error("IMAPConnection.fetchStream requires a message uid.")
     }
     if (!options) {
       throw new Error("IMAPConnection.fetchStream requires an options object.")
     }
     return new Promise((resolve, reject) => {
-      const f = this._imap.fetch(messageId, options);
+      const f = this._imap.fetch(uid, options);
       f.on('message', (imapMessage) => {
         imapMessage.on('body', (stream) => {
           resolve(stream)
         })
       })
-      f.once('error', (error) => reject)
+      f.once('error', reject)
     })
   }
 
diff --git a/packages/nylas-core/models/account/file.js b/packages/nylas-core/models/account/file.js
index 90e196c90..a73ed0844 100644
--- a/packages/nylas-core/models/account/file.js
+++ b/packages/nylas-core/models/account/file.js
@@ -26,7 +26,7 @@ module.exports = (sequelize, Sequelize) => {
           return message.getFolder()
           .then((folder) => connection.openBox(folder.name))
           .then((imapBox) => imapBox.fetchStream({
-            messageId: message.folderUID,
+            uid: message.folderImapUID,
             options: {
               bodies: [this.partId],
               struct: true,