diff --git a/internal_packages/account-sidebar/lib/sidebar-item.coffee b/internal_packages/account-sidebar/lib/sidebar-item.coffee
index 18609930a..75f1dd4d7 100644
--- a/internal_packages/account-sidebar/lib/sidebar-item.coffee
+++ b/internal_packages/account-sidebar/lib/sidebar-item.coffee
@@ -60,15 +60,26 @@ class SidebarItem
       dataTransferType: 'nylas-thread-ids'
       onDelete: onDeleteItem
       onToggleCollapsed: toggleItemCollapsed
-      onDrop: (item, ids) ->
+      onDrop: (item, event) ->
+        jsonString = event.dataTransfer.getData(item.dataTransferType)
+        ids = null
+        try
+          ids = JSON.parse(jsonString);
+        catch err
+          console.error('OutlineViewItem onDrop: JSON parse #{err}');
         return unless ids
         item.perspective.applyToThreads(ids)
       shouldAcceptDrop: (item, event) ->
-        perspective = item.perspective
-        return false unless perspective
-        return false if perspective.isEqual(FocusedPerspectiveStore.current())
-        return false unless perspective.canApplyToThreads()
-        item.dataTransferType in event.dataTransfer.types
+        target = item.perspective
+        current = FocusedPerspectiveStore.current()
+
+        return false unless target
+        return false if target.isEqual(current)
+        return false unless _.isEqual(target.accountIds, current.accountIds)
+        return false unless target.canApplyToThreads()
+
+        return item.dataTransferType in event.dataTransfer.types
+
       onSelect: (item) ->
         Actions.selectRootSheet(WorkspaceStore.Sheet.Threads)
         Actions.focusMailboxPerspective(item.perspective)
diff --git a/src/components/list-tabular.cjsx b/src/components/list-tabular.cjsx
index d0d4969fe..04ec398ad 100644
--- a/src/components/list-tabular.cjsx
+++ b/src/components/list-tabular.cjsx
@@ -108,6 +108,8 @@ class ListTabular extends React.Component
     @setState(@buildStateForRange(start: rangeStart, end: rangeEnd))
 
   render: =>
+    otherProps = _.omit(@props, _.keys(@constructor.propTypes))
+
     innerStyles =
       height: @state.count * @props.itemHeight
 
@@ -122,7 +124,7 @@ class ListTabular extends React.Component
         tabIndex="-1"
         className="list-container list-tabular"
         scrollTooltipComponent={@props.scrollTooltipComponent}>
-        <div className="list-rows" style={innerStyles}>
+        <div className="list-rows" style={innerStyles} {...otherProps}>
           {@_rows()}
         </div>
       </ScrollRegion>
diff --git a/src/components/outline-view-item.jsx b/src/components/outline-view-item.jsx
index d00020f32..c4cbeafd6 100644
--- a/src/components/outline-view-item.jsx
+++ b/src/components/outline-view-item.jsx
@@ -64,8 +64,9 @@ class OutlineViewItem extends Component {
   _runCallback = (method, ...args)=> {
     const item = this.props.item;
     if (item[method]) {
-      item[method](item, ...args);
+      return item[method](item, ...args);
     }
+    return undefined;
   }
 
 
@@ -76,17 +77,7 @@ class OutlineViewItem extends Component {
   }
 
   _onDrop = (event)=> {
-    const item = this.props.item;
-    const jsonString = event.dataTransfer.getData(item.dataTransferType);
-    let ids;
-    try {
-      ids = JSON.parse(jsonString);
-    } catch (err) {
-      console.error('OutlineViewItem onDrop: JSON parse #{err}');
-    }
-    if (!ids) return;
-
-    this._runCallback('onDrop', ids);
+    this._runCallback('onDrop', event);
   }
 
   _onToggleCollapsed = ()=> {
@@ -103,7 +94,7 @@ class OutlineViewItem extends Component {
   }
 
   _shouldAcceptDrop = (event)=> {
-    this._runCallback('shouldAcceptDrop', event);
+    return this._runCallback('shouldAcceptDrop', event);
   }
 
   _onShowContextMenu = ()=> {
diff --git a/src/flux/models/query-result-set.coffee b/src/flux/models/query-result-set.coffee
index 6451b0c2b..8dc6af1e2 100644
--- a/src/flux/models/query-result-set.coffee
+++ b/src/flux/models/query-result-set.coffee
@@ -96,7 +96,7 @@ class QueryResultSet
     if @_idToIndexHash is null
       @buildIdToIndexHash()
 
-    if @_idToIndexHash[id]
+    if @_idToIndexHash[id] isnt undefined
       return @_idToIndexHash[id] + @_offset
     else
       return -1
diff --git a/src/mailbox-perspective.coffee b/src/mailbox-perspective.coffee
index 275b7dcdf..12e1d87d5 100644
--- a/src/mailbox-perspective.coffee
+++ b/src/mailbox-perspective.coffee
@@ -1,5 +1,6 @@
 _ = require 'underscore'
 
+TaskFactory = require './flux/tasks/task-factory'
 AccountStore = require './flux/stores/account-store'
 CategoryStore = require './flux/stores/category-store'
 DatabaseStore = require './flux/stores/database-store'
@@ -233,31 +234,14 @@ class CategoryMailboxPerspective extends MailboxPerspective
     super
 
   applyToThreads: (threadsOrIds) =>
-    # TODO:
-    # categoryToApplyForAccount = {}
-    # for cat in @_categories
-    #   categoryToApplyForAccount[cat.accountId] = cat
-    #
-    # @_categories.forEach (cat) ->
-    #
-    # if @account.usesLabels()
-    #   FocusedPerspectiveStore = require './flux/stores/focused-perspective-store'
-    #   currentLabel = FocusedPerspectiveStore.current().category
-    #   if currentLabel and not (currentLabel.isLockedCategory())
-    #     labelsToRemove = [currentLabel]
-    #
-    #   ChangeLabelsTask = require './flux/tasks/change-labels-task'
-    #   task = new ChangeLabelsTask
-    #     threads: threadsOrIds
-    #     labelsToAdd: [@category]
-    #     labelsToRemove: labelsToRemove
-    # else
-    #   ChangeFolderTask = require './flux/tasks/change-folder-task'
-    #   task = new ChangeFolderTask
-    #     threads: threadsOrIds
-    #     folder: @category
-    #
-    # Actions.queueTask(task)
+    FocusedPerspectiveStore = require './flux/stores/focused-perspective-store'
+    currentCategories = FocusedPerspectiveStore.current().categories()
 
+    DatabaseStore.modelify(Thread, threadsOrIds).then (threads) =>
+      tasks = TaskFactory.tasksForApplyingCategories
+        threads: threads
+        categoriesToRemove: (accountId) -> _.filter(currentCategories, _.matcher({accountId}))
+        categoryToAdd: (accountId) => _.findWhere(@_categories, {accountId})
+      Actions.queueTasks(tasks)
 
 module.exports = MailboxPerspective