diff --git a/calendar/js/et2_widget_event.js b/calendar/js/et2_widget_event.js
index 8a3e17e9f2..9affd80764 100644
--- a/calendar/js/et2_widget_event.js
+++ b/calendar/js/et2_widget_event.js
@@ -918,7 +918,7 @@ et2_calendar_event.owner_check = function owner_check(event, parent, owner_too)
 	{
 		owner_too = app.calendar.state.status_filter === 'owner';
 	}
-	var options = false
+	var options = false;
 	if(app.calendar && app.calendar.sidebox_et2 && app.calendar.sidebox_et2.getWidgetById('owner'))
 	{
 		options = app.calendar.sidebox_et2.getWidgetById('owner').taglist.getSelection();
diff --git a/calendar/js/et2_widget_planner.js b/calendar/js/et2_widget_planner.js
index f68027015a..70411e9c6b 100644
--- a/calendar/js/et2_widget_planner.js
+++ b/calendar/js/et2_widget_planner.js
@@ -363,10 +363,50 @@ var et2_calendar_planner = (function(){ "use strict"; return et2_calendar_view.e
 			row_labels: function() {
 				var labels = [];
 				var already_added = [];
+				var options = false;
+				if(app.calendar && app.calendar.sidebox_et2 && app.calendar.sidebox_et2.getWidgetById('owner'))
+				{
+					options = app.calendar.sidebox_et2.getWidgetById('owner').taglist.getSelection();
+				}
+				else
+				{
+					options = this.getArrayMgr("sel_options").getRoot().getEntry('owner');
+				}
 				for(var i = 0; i < this.options.owner.length; i++)
 				{
 					var user = this.options.owner[i];
-					if (user < 0)	// groups
+					// Handle grouped resources like mailing lists - pull it from sidebox owner
+					// and expand to their contents
+					if(isNaN(user) && options && options.find)
+					{
+						var resource = options.find(function(element) {return element.id == user;}) || {};
+						if(resource && resource.resources)
+						{
+							for(var j = 0; j < resource.resources.length; j++)
+							{
+								var id = resource.resources[j];
+								if(already_added.indexOf(''+id) < 0)
+								{
+									labels.push({
+										id: id,
+										label: this._get_owner_name(id),
+										data: {participants:id,owner:id}
+									});
+									already_added.push(''+id);
+								}
+							}
+						}
+						else if(already_added.indexOf(''+user) < 0)
+						{
+							labels.push({
+								id: user,
+								label: this._get_owner_name(user),
+								data: {participants:id,owner:id}
+							});
+							already_added.push(''+user);
+						}
+					}
+					else if (user < 0)	// groups
 					{
 						egw.accountData(user,'account_fullname',true,function(result) {
 							for(var id in result)
diff --git a/calendar/js/et2_widget_view.js b/calendar/js/et2_widget_view.js
index 8a4ecdcbd6..1f3d005347 100644
--- a/calendar/js/et2_widget_view.js
+++ b/calendar/js/et2_widget_view.js
@@ -322,6 +322,10 @@ var et2_calendar_view = (function(){ "use strict"; return et2_valueWidget.extend
 			// 0 means current user
 			user = egw.user('account_id');
 		}
+		if(et2_calendar_view.owner_name_cache[user])
+		{
+			return et2_calendar_view.owner_name_cache[user];
+		}
 		if (!isNaN(user))
 		{
 			user = parseInt(user);
@@ -349,16 +353,23 @@ var et2_calendar_view = (function(){ "use strict"; return et2_valueWidget.extend
 			}
 			if(options && options.find)
 			{
-				user = options.find(function(element) {return element.id == user;}) || {};
-				label = user.label;
+				var found = options.find(function(element) {return element.id == user;}) || {};
+				if(found && found.label)
+				{
+					label = found.label;
+				}
 			}
-			else
+			if(!label)
 			{
 				// No sidebox?  Must be in home or sitemgr (no caching) - ask directly
 				label = '?';
 				egw.json('calendar_owner_etemplate_widget::ajax_owner',user,function(data) {label = data;}, this).sendRequest();
 			}
 		}
+		if(label)
+		{
+			et2_calendar_view.owner_name_cache[user] = label;
+		}
 		return label;
 	},
 
@@ -592,6 +603,11 @@ jQuery.extend(et2_calendar_view,
 		);
 	},
 
+	/**
+	 * Cache to map owner & resource IDs to names, helps cut down on server requests
+	 */
+	owner_name_cache: {},
+
 	holiday_cache: {},
 	/**
 	 * Fetch and cache a list of the year's holidays