diff --git a/apps/common/Gateway.js b/apps/common/Gateway.js
index fb36487309..031afc7dae 100644
--- a/apps/common/Gateway.js
+++ b/apps/common/Gateway.js
@@ -358,8 +358,8 @@ if (window.Common === undefined) {
                 _postMessage({event:'onMakeActionLink', data: config});
             },
 
-            requestUsers:  function (command, id) {
-                _postMessage({event:'onRequestUsers', data: {c: command, id: id}});
+            requestUsers:  function (command, id, from, count, search) { // from, count, search are used for mentions
+                _postMessage({event:'onRequestUsers', data: {c: command, id: id, from: from, count: count, search: search}});
             },
 
             requestSendNotify:  function (emails) {
diff --git a/apps/common/main/lib/controller/ExternalUsers.js b/apps/common/main/lib/controller/ExternalUsers.js
index d939a32ded..71b3755a87 100644
--- a/apps/common/main/lib/controller/ExternalUsers.js
+++ b/apps/common/main/lib/controller/ExternalUsers.js
@@ -51,7 +51,7 @@ Common.UI.ExternalUsers = new( function() {
         api,
         userColors = [];
 
-    var _get = function(type, ids) {
+    var _get = function(type, ids, from, count, search) {
         if (type==='info') {
             (typeof ids !== 'object') && (ids = [ids]);
             ids && (ids = _.uniq(ids));
@@ -67,7 +67,7 @@ Common.UI.ExternalUsers = new( function() {
             type = type || 'mention';
             if (externalUsers[type]===undefined) {
                 isUsersLoading = true;
-                Common.Gateway.requestUsers(type || 'mention');
+                Common.Gateway.requestUsers(type || 'mention', undefined, from || 0, count || 100, search || '');
             } else {
                 Common.NotificationCenter.trigger('mentions:setusers', type, externalUsers[type]);
             }
@@ -125,10 +125,12 @@ Common.UI.ExternalUsers = new( function() {
                 externalUsers = [];
                 return;
             }
-            var type = data.c || 'mention';
-            externalUsers[type] = data.users || [];
+            var type = data.c || 'mention',
+                users = data.users || [];
+            if (data.total===undefined) // use old scheme
+                externalUsers[type] = users;
             isUsersLoading = false;
-            Common.NotificationCenter.trigger('mentions:setusers', type, externalUsers[type]);
+            Common.NotificationCenter.trigger('mentions:setusers', type, users, data.total);
         });
 
         Common.NotificationCenter.on('mentions:clearusers',   function(type) {
diff --git a/apps/common/main/lib/view/ReviewPopover.js b/apps/common/main/lib/view/ReviewPopover.js
index a2fc67a327..00bddd2d70 100644
--- a/apps/common/main/lib/view/ReviewPopover.js
+++ b/apps/common/main/lib/view/ReviewPopover.js
@@ -1123,6 +1123,8 @@ define([
                     me.e = event;
                 });
                 textBox && textBox.on('input', function (event) {
+                    clearTimeout(me._state.timerEmailList);
+
                     var $this = $(this),
                         start = this.selectionStart,
                         val = $this.val(),
@@ -1141,7 +1143,9 @@ define([
                         res = str.match(/^(?:[@]|[+](?!1))(\S*)/);
                     if (res && res.length>1) {
                         str = res[1]; // send to show email menu
-                        me.onEmailListMenu(str, left, right);
+                        me._state.timerEmailList = setTimeout(function () {
+                            me.onEmailListMenu(str, left, right);
+                        }, 300);
                     } else
                         me.onEmailListMenu(); // hide email menu
                 });
@@ -1210,29 +1214,46 @@ define([
         },
 
         onEmailListMenu: function(str, left, right) {
+            clearTimeout(this._state.timerEmailList);
             if (typeof str == 'string') {
                 this._state.emailSearch = {
                     str: str,
                     left: left,
-                    right: right
+                    right: right,
+                    from: 0,
+                    count: 100,
+                    total: undefined,
+                    scrollTop: 0
                 };
-                Common.UI.ExternalUsers.get('mention');
+                var data = this._state.emailSearch;
+                Common.UI.ExternalUsers.get('mention', undefined, data.from, data.count, data.str);
             } else {
                 this._state.emailSearch = null;
                 this.emailMenu.rendered && this.emailMenu.cmpEl.css('display', 'none');
             }
         },
 
-        onEmailListMenuCallback: function(type, users) {
+        onEmailListMenuNext: function() {
+            var data = this._state.emailSearch;
+            if (data && data.total!==undefined && data.from + data.count < data.total) {
+                data.from += data.count;
+                Common.UI.ExternalUsers.get('mention', undefined, data.from, data.count, data.str);
+            }
+        },
+
+        onEmailListMenuCallback: function(type, users, total) {
             if (!this._state.emailSearch || users.length<1 || type && type!=='mention') return;
 
             var me   = this,
                 menu = me.emailMenu,
                 str = this._state.emailSearch.str,
                 left = this._state.emailSearch.left,
-                right = this._state.emailSearch.right;
+                right = this._state.emailSearch.right,
+                from = this._state.emailSearch.from,
+                isClientSearch = total===undefined;// || from===0 && !str && total<this._state.emailSearch.count; ???
 
-            this._state.emailSearch = null;
+            this._state.emailSearch.total = total;
+            isClientSearch && (this._state.emailSearch = null);
 
             var menuContainer = me.$window.find(Common.Utils.String.format('#menu-container-{0}', menu.id)),
                 textbox = this.commentsView.getTextBox(),
@@ -1255,29 +1276,39 @@ define([
                         tb && tb.focus();
                     }, 10);
                 });
+                !isClientSearch && menu.scroller.cmpEl.on('scroll', function (event) {
+                    let st = $(event.target).scrollTop();
+                    if (me._state.emailSearch && me._state.emailSearch.scrollTop < st)
+                        me.onEmailListMenuNext();
+                    me._state.emailSearch.scrollTop = st;
+                });
             }
 
-            for (var i = 0; i < menu.items.length; i++) {
-                menu.removeItem(menu.items[i]);
-                i--;
+            if (isClientSearch || from===0) {
+                for (var i = 0; i < menu.items.length; i++) {
+                    menu.removeItem(menu.items[i]);
+                    i--;
+                }
             }
 
             if (users.length>0) {
-                str = str.toLowerCase();
-                if (str.length>0) {
-                    users = _.filter(users, function(item) {
-                        if (item.email && 0 === item.email.toLowerCase().indexOf(str)) return true;
+                if (isClientSearch) {
+                    str = str.toLowerCase();
+                    if (str.length>0) {
+                        users = _.filter(users, function(item) {
+                            if (item.email && 0 === item.email.toLowerCase().indexOf(str)) return true;
 
-                        let arr = item.name ? item.name.toLowerCase().split(' ') : [],
-                            inName = false;
-                        for (let i=0; i<arr.length; i++) {
-                            if (0 === arr[i].indexOf(str)) {
-                                inName = true;
-                                break;
+                            let arr = item.name ? item.name.toLowerCase().split(' ') : [],
+                                inName = false;
+                            for (let i=0; i<arr.length; i++) {
+                                if (0 === arr[i].indexOf(str)) {
+                                    inName = true;
+                                    break;
+                                }
                             }
-                        }
-                        return inName;
-                    });
+                            return inName;
+                        });
+                    }
                 }
                 var tpl = _.template('<a id="<%= id %>" tabindex="-1" type="menuitem">' +
                                         '<div style="overflow: hidden; text-overflow: ellipsis; max-width: 195px;"><%= Common.Utils.String.htmlEncode(caption) %></div>' +