diff --git a/src/Oro/Bundle/ActivityListBundle/Resources/translations/messages.en.yml b/src/Oro/Bundle/ActivityListBundle/Resources/translations/messages.en.yml
index 6d4a29cd4ec..1bf2dc643ed 100644
--- a/src/Oro/Bundle/ActivityListBundle/Resources/translations/messages.en.yml
+++ b/src/Oro/Bundle/ActivityListBundle/Resources/translations/messages.en.yml
@@ -38,7 +38,7 @@ oro:
                 per_page.label: Items Per Page By Default
             email_threads:
                 use_threads_in_activities:
-                    label: Display Emails in Activities as
+                    label: Display email conversations in activity lists as
                     choices:
                         non_threaded.label: Non-Threaded
                         threaded.label: Threaded
diff --git a/src/Oro/Bundle/AddressBundle/Resources/public/js/address/model.js b/src/Oro/Bundle/AddressBundle/Resources/public/js/address/model.js
index c3e42cc39ac..17acc87152e 100644
--- a/src/Oro/Bundle/AddressBundle/Resources/public/js/address/model.js
+++ b/src/Oro/Bundle/AddressBundle/Resources/public/js/address/model.js
@@ -33,9 +33,28 @@ define([
         },
 
         getSearchableString: function() {
-            return this.get('country') + ', ' +
-                this.get('city') + ', ' +
-                this.get('street') + ' ' + (this.get('street2') || '');
+            var address = '';
+
+            if (this.get('country')) {
+                address += this.get('country') + ', ';
+            }
+            if (this.get('region')) {
+                address += this.get('region') + ', ';
+            }
+            if (this.get('city')) {
+                address += this.get('city') + ', ';
+            }
+            if (this.get('street')) {
+                address += this.get('street') + ' ';
+            }
+            if (this.get('street2')) {
+                address += this.get('street2') + ' ';
+            }
+            if (this.get('postalCode')) {
+                address += this.get('postalCode') + ', ';
+            }
+
+            return address;
         }
     });
 });
diff --git a/src/Oro/Bundle/ApiBundle/Resources/doc/how_to.md b/src/Oro/Bundle/ApiBundle/Resources/doc/how_to.md
index 7e8fedb64b5..7618438bfa6 100644
--- a/src/Oro/Bundle/ApiBundle/Resources/doc/how_to.md
+++ b/src/Oro/Bundle/ApiBundle/Resources/doc/how_to.md
@@ -25,6 +25,14 @@ oro_api:
         Acme\Bundle\ProductBundle\Product: ~
 ```
 
+**Attention**: In version 2.0, use:
+ 
+```yaml
+api:
+    entities:
+        Acme\Bundle\ProductBundle\Product: ~
+```
+ 
 Turn on API for entity disabled in Resources/config/oro/entity.yml
 ------------------------------------------------------------------
 
@@ -117,7 +125,7 @@ oro_api:
         Acme\Bundle\ProductBundle\Product:
             actions:
                 delete:
-                    excluded: true
+                    exclude: true
 ```
 
 Also, you can use short syntax:
diff --git a/src/Oro/Bundle/BatchBundle/ORM/QueryBuilder/CountQueryBuilderOptimizer.php b/src/Oro/Bundle/BatchBundle/ORM/QueryBuilder/CountQueryBuilderOptimizer.php
index 56cb89ed8eb..31ed4af4d3c 100644
--- a/src/Oro/Bundle/BatchBundle/ORM/QueryBuilder/CountQueryBuilderOptimizer.php
+++ b/src/Oro/Bundle/BatchBundle/ORM/QueryBuilder/CountQueryBuilderOptimizer.php
@@ -48,6 +48,7 @@ public function setEventDispatcher(EventDispatcherInterface $eventDispatcher)
      * Get optimized query builder for count calculation.
      *
      * @param QueryBuilder $queryBuilder
+     *
      * @return QueryBuilder
      * @throws \Exception
      */
@@ -60,11 +61,9 @@ public function getCountQueryBuilder(QueryBuilder $queryBuilder)
             $this->context = null;
 
             return $qb;
-        } catch (\Exception $e) {
+        } finally {
             // make sure that a link to the context is removed even if an exception occurred
             $this->context = null;
-            // rethrow an exception
-            throw $e;
         }
     }
 
@@ -159,43 +158,52 @@ protected function addJoins(
         $havingAliases  = $this->qbTools->getUsedTableAliases($originalQueryParts['having']);
         $joinAliases    = array_merge($whereAliases, $groupByAliases, $havingAliases);
         $joinAliases    = array_unique($joinAliases);
+        $fromQueryPart = $originalQueryParts['from'];
+        $joinQueryPart = $originalQueryParts['join'];
 
         // this joins cannot be removed outside of this class
         $requiredJoinAliases = $joinAliases;
 
-        if ($useNonSymmetricJoins) {
-            $joinAliases = array_merge(
-                $joinAliases,
-                $this->getNonSymmetricJoinAliases(
-                    $originalQueryParts['from'],
-                    $originalQueryParts['join'],
-                    $groupByAliases
-                )
-            );
-        }
+        $rootAliases = array_map(
+            function ($from) {
+                return $from->getAlias();
+            },
+            $fromQueryPart
+        );
+
+        $joinAliases = $this->addRequiredJoins(
+            $joinAliases,
+            $fromQueryPart,
+            $joinQueryPart,
+            $groupByAliases,
+            $useNonSymmetricJoins
+        );
+
+        $requiredJoinAliases = array_intersect(
+            array_diff($requiredJoinAliases, $rootAliases),
+            $this->context->getAliases()
+        );
+
+        $collectedAliases = $joinAliases;
+        $joinAliases = $this->dispatchQueryOptimizationEvent($joinAliases, $requiredJoinAliases);
 
-        $rootAliases = [];
-        /** @var Expr\From $from */
-        foreach ($originalQueryParts['from'] as $from) {
-            $rootAliases[] = $from->getAlias();
-            $joinAliases   = array_merge(
-                $joinAliases,
-                $this->qbTools->getUsedJoinAliases($originalQueryParts['join'], $joinAliases, $from->getAlias())
+        // additional check joins after the events in case if events change joins list
+        if (count($joinAliases) !== count($collectedAliases)) {
+            $joinAliases = $this->addRequiredJoins(
+                $requiredJoinAliases,
+                $fromQueryPart,
+                $this->removeAliasesFromQueryJoinParts($joinQueryPart, $joinAliases),
+                $groupByAliases,
+                $useNonSymmetricJoins
             );
         }
 
-        $allAliases          = $this->context->getAliases();
-        $joinAliases         = array_intersect(array_diff(array_unique($joinAliases), $rootAliases), $allAliases);
-        $requiredJoinAliases = array_intersect(array_diff($requiredJoinAliases, $rootAliases), $allAliases);
-
-        $joinAliases = $this->dispatchQueryOptimizationEvent($joinAliases, $requiredJoinAliases);
-
         foreach ($rootAliases as $rootAlias) {
-            if (!isset($originalQueryParts['join'][$rootAlias])) {
+            if (!isset($joinQueryPart[$rootAlias])) {
                 continue;
             }
             /** @var Expr\Join $join */
-            foreach ($originalQueryParts['join'][$rootAlias] as $join) {
+            foreach ($joinQueryPart[$rootAlias] as $join) {
                 $alias = $join->getAlias();
                 // To count results number join all tables with inner join and required to tables
                 if ($join->getJoinType() === Expr\Join::INNER_JOIN || in_array($alias, $joinAliases, true)) {
@@ -421,6 +429,7 @@ protected function getAssociationType($entityClass, $associationName, $targetEnt
      * then them also should be selected as DISTINCT in optimized Query Builder.
      *
      * @param array $originalQueryParts
+     *
      * @return array
      */
     protected function getFieldsToSelect(array $originalQueryParts)
@@ -452,4 +461,76 @@ protected function getFieldsToSelect(array $originalQueryParts)
 
         return $fieldsToSelect;
     }
+
+    /**
+     * Removes list of aliases from original query parts
+     *
+     * @param array $originalQueryParts
+     * @param array $joinAliases
+     *
+     * @return array
+     */
+    protected function removeAliasesFromQueryJoinParts(array $originalQueryParts, array $joinAliases)
+    {
+        $filteredJoins = [];
+        foreach ($originalQueryParts as $root => $joins) {
+            foreach ($joins as $declaration) {
+                /** @var Expr\Join $name */
+                $name = $declaration->getAlias();
+                if (in_array($name, $joinAliases)) {
+                    if (!array_key_exists($root, $filteredJoins)) {
+                        $filteredJoins[$root] = [];
+                    }
+                    $filteredJoins[$root][] = $declaration;
+                }
+            }
+        }
+
+        return $filteredJoins;
+    }
+
+    /**
+     * Collect and add the joins should be added to query
+     *
+     * @param array   $joinAliases
+     * @param array   $fromQueryPart
+     * @param array   $joinQueryPart
+     * @param array   $groupByAliases
+     * @param boolean $useNonSymmetricJoins
+     *
+     * @return array
+     */
+    protected function addRequiredJoins(
+        array $joinAliases,
+        array $fromQueryPart,
+        array $joinQueryPart,
+        array $groupByAliases,
+        $useNonSymmetricJoins
+    ) {
+        if ($useNonSymmetricJoins) {
+            $joinAliases = array_merge(
+                $joinAliases,
+                $this->getNonSymmetricJoinAliases(
+                    $fromQueryPart,
+                    $joinQueryPart,
+                    $groupByAliases
+                )
+            );
+        }
+
+        $rootAliases = [];
+        /** @var Expr\From $from */
+        foreach ($fromQueryPart as $from) {
+            $rootAliases[] = $from->getAlias();
+            $joinAliases = array_merge(
+                $joinAliases,
+                $this->qbTools->getUsedJoinAliases($joinQueryPart, $joinAliases, $from->getAlias())
+            );
+        }
+
+        $allAliases = $this->context->getAliases();
+        $joinAliases = array_intersect(array_diff(array_unique($joinAliases), $rootAliases), $allAliases);
+
+        return $joinAliases;
+    }
 }
diff --git a/src/Oro/Bundle/BatchBundle/Tests/Unit/ORM/QueryBuilder/CountQueryBuilderOptimizerTest.php b/src/Oro/Bundle/BatchBundle/Tests/Unit/ORM/QueryBuilder/CountQueryBuilderOptimizerTest.php
index fc102fd3677..4ba76079302 100644
--- a/src/Oro/Bundle/BatchBundle/Tests/Unit/ORM/QueryBuilder/CountQueryBuilderOptimizerTest.php
+++ b/src/Oro/Bundle/BatchBundle/Tests/Unit/ORM/QueryBuilder/CountQueryBuilderOptimizerTest.php
@@ -8,8 +8,11 @@
 use Doctrine\ORM\Query\Expr\Join;
 use Doctrine\ORM\QueryBuilder;
 
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+
 use Oro\Component\TestUtils\ORM\Mocks\EntityManagerMock;
 use Oro\Component\TestUtils\ORM\OrmTestCase;
+use Oro\Bundle\BatchBundle\Event\CountQueryOptimizationEvent;
 use Oro\Bundle\BatchBundle\ORM\QueryBuilder\CountQueryBuilderOptimizer;
 
 class CountQueryBuilderOptimizerTest extends OrmTestCase
@@ -534,4 +537,132 @@ public static function createQueryBuilder(EntityManager $entityManager)
     {
         return new QueryBuilder($entityManager);
     }
+
+    /**
+     * @dataProvider getCountQueryBuilderDataProviderWithEventDispatcher
+     *
+     * @param callback $queryBuilder
+     * @param array    $joinsToDelete
+     * @param string   $expectedDql
+     */
+    public function testGetCountQueryBuilderWithEventDispatcher($queryBuilder, array $joinsToDelete, $expectedDql)
+    {
+        $optimizer = new CountQueryBuilderOptimizer();
+        $eventDispatcher = $this->getMockBuilder(EventDispatcherInterface::class)->getMock();
+        $eventDispatcher->expects($this->once())
+            ->method('dispatch')
+            ->willReturnCallback(
+                function ($eventName, CountQueryOptimizationEvent $event) use ($joinsToDelete) {
+                    if (count($joinsToDelete)) {
+                        foreach ($joinsToDelete as $deletedJoin) {
+                            $event->removeJoinFromOptimizedQuery($deletedJoin);
+                        }
+                    }
+                }
+            );
+        $optimizer->setEventDispatcher($eventDispatcher);
+        $countQb = $optimizer->getCountQueryBuilder(call_user_func($queryBuilder, $this->em));
+
+        $this->assertInstanceOf('Doctrine\ORM\QueryBuilder', $countQb);
+        // Check for expected DQL
+        $this->assertEquals($expectedDql, $countQb->getQuery()->getDQL());
+        // Check that Optimized DQL can be converted to SQL
+        $this->assertNotEmpty($countQb->getQuery()->getSQL());
+    }
+
+    public function getCountQueryBuilderDataProviderWithEventDispatcher()
+    {
+        return [
+            'delete_one_join_table'                                     => [
+                'queryBuilder' => function ($em) {
+                    return self::createQueryBuilder($em)
+                        ->from('Test:User', 'u')
+                        ->leftJoin('u.businessUnits', 'bu', Join::WITH, 'bu.id = 456')
+                        ->leftJoin('bu.users', 'o', Join::WITH, 'o.id = 123')
+                        ->select('u.id, o.username');
+                },
+                ['o'],
+                'expectedDQL'  => 'SELECT u.id FROM Test:User u '
+                    . 'LEFT JOIN u.businessUnits bu WITH bu.id = 456'
+            ],
+            'request_with_3th_join_table_without_deleting'              => [
+                'queryBuilder' => function ($em) {
+                    return self::createQueryBuilder($em)
+                        ->from('Test:User', 'u')
+                        ->leftJoin('u.organization', 'o', Join::WITH, 'o.id = 456')
+                        ->leftJoin('o.businessUnits', 'businessUnits', Join::WITH, 'businessUnits.id = 123')
+                        ->select('u.id, o.username');
+                },
+                [],
+                'expectedDQL'  => 'SELECT u.id FROM Test:User u '
+                    . 'LEFT JOIN u.organization o WITH o.id = 456 '
+                    . 'LEFT JOIN o.businessUnits businessUnits WITH businessUnits.id = 123'
+            ],
+            'request_with_3th_join_table_delete_main_join_table'        => [
+                'queryBuilder' => function ($em) {
+                    return self::createQueryBuilder($em)
+                        ->from('Test:User', 'u')
+                        ->leftJoin('u.organization', 'o', Join::WITH, 'o.id = 456')
+                        ->leftJoin('o.businessUnits', 'businessUnits', Join::WITH, 'businessUnits.id = 123')
+                        ->select('u.id, o.username');
+                },
+                ['o'],
+                'expectedDQL'  => 'SELECT u.id FROM Test:User u LEFT '
+                    . 'JOIN u.organization o WITH o.id = 456 '
+                    . 'LEFT JOIN o.businessUnits businessUnits WITH businessUnits.id = 123'
+            ],
+            'request_with_3th_join_table_delete_3th_join_table'         => [
+                'queryBuilder' => function ($em) {
+                    return self::createQueryBuilder($em)
+                        ->from('Test:User', 'u')
+                        ->leftJoin('u.organization', 'o', Join::WITH, 'o.id = 456')
+                        ->leftJoin('o.businessUnits', 'businessUnits', Join::WITH, 'businessUnits.id = 123')
+                        ->select('u.id, o.username');
+                },
+                ['businessUnits'],
+                'expectedDQL'  => 'SELECT u.id FROM Test:User u'
+            ],
+            'request_with_2_3th_join_tables_without_deleting'           => [
+                'queryBuilder' => function ($em) {
+                    return self::createQueryBuilder($em)
+                        ->from('Test:User', 'u')
+                        ->leftJoin('u.organization', 'o', Join::WITH, 'o.id = 456')
+                        ->leftJoin('o.businessUnits', 'businessUnits', Join::WITH, 'businessUnits.id = 123')
+                        ->leftJoin('o.users', 'users', Join::WITH, 'users.id = 123')
+                        ->select('u.id, o.username');
+                },
+                [],
+                'expectedDQL'  => 'SELECT u.id FROM Test:User u '
+                    . 'LEFT JOIN u.organization o WITH o.id = 456 '
+                    . 'LEFT JOIN o.businessUnits businessUnits WITH businessUnits.id = 123 '
+                    . 'LEFT JOIN o.users users WITH users.id = 123'
+            ],
+            'request_with_2_3th_join_tables_delete_3th_join_table'      => [
+                'queryBuilder' => function ($em) {
+                    return self::createQueryBuilder($em)
+                        ->from('Test:User', 'u')
+                        ->leftJoin('u.organization', 'o', Join::WITH, 'o.id = 456')
+                        ->leftJoin('o.businessUnits', 'businessUnits', Join::WITH, 'businessUnits.id = 123')
+                        ->leftJoin('o.users', 'users', Join::WITH, 'users.id = 123')
+                        ->select('u.id, o.username');
+                },
+                ['businessUnits'],
+                'expectedDQL'  => 'SELECT u.id FROM Test:User u '
+                    . 'LEFT JOIN u.organization o WITH o.id = 456 '
+                    . 'LEFT JOIN o.users users WITH users.id = 123'
+            ],
+            'request_with_2_3th_join_tables_delete_both_3th_join_table' => [
+                'queryBuilder' => function ($em) {
+                    return self::createQueryBuilder($em)
+                        ->from('Test:User', 'u')
+                        ->leftJoin('u.organization', 'o', Join::WITH, 'o.id = 456')
+                        ->leftJoin('o.businessUnits', 'businessUnits', Join::WITH, 'businessUnits.id = 123')
+                        ->leftJoin('o.users', 'users', Join::WITH, 'users.id = 123')
+                        ->select('u.id, o.username');
+                },
+                ['businessUnits', 'users'],
+                'expectedDQL'  => 'SELECT u.id FROM Test:User u'
+            ]
+        ];
+    }
 }
diff --git a/src/Oro/Bundle/ChartBundle/Resources/public/js/app/components/horizontal_bar-chart-component.js b/src/Oro/Bundle/ChartBundle/Resources/public/js/app/components/horizontal_bar-chart-component.js
index 121f0482c24..eb21a340474 100644
--- a/src/Oro/Bundle/ChartBundle/Resources/public/js/app/components/horizontal_bar-chart-component.js
+++ b/src/Oro/Bundle/ChartBundle/Resources/public/js/app/components/horizontal_bar-chart-component.js
@@ -97,6 +97,15 @@ define(function(require) {
                         }
                     },
                     yaxis: {
+                        ticks: function() {
+                            var ticks = [];
+                            for (var i in yLabels) {
+                                if (yLabels[i]) {
+                                    ticks.push([i, yLabels[i]]);
+                                }
+                            }
+                            return ticks;
+                        },
                         tickFormatter: function(x) {
                             return yLabels[parseInt(x)];
                         }
diff --git a/src/Oro/Bundle/DataAuditBundle/Entity/Repository/AuditRepository.php b/src/Oro/Bundle/DataAuditBundle/Entity/Repository/AuditRepository.php
index 7b6bab4cacd..d00be047f73 100644
--- a/src/Oro/Bundle/DataAuditBundle/Entity/Repository/AuditRepository.php
+++ b/src/Oro/Bundle/DataAuditBundle/Entity/Repository/AuditRepository.php
@@ -7,6 +7,11 @@
 
 class AuditRepository extends LogEntryRepository
 {
+    /**
+     * @param object $entity
+     *
+     * @return \Doctrine\ORM\QueryBuilder
+     */
     public function getLogEntriesQueryBuilder($entity)
     {
         $wrapped     = new EntityWrapper($entity, $this->_em);
diff --git a/src/Oro/Bundle/DataGridBundle/Resources/doc/backend/extensions/field_acl.md b/src/Oro/Bundle/DataGridBundle/Resources/doc/backend/extensions/field_acl.md
index 9b141c475fd..610c0559bb8 100644
--- a/src/Oro/Bundle/DataGridBundle/Resources/doc/backend/extensions/field_acl.md
+++ b/src/Oro/Bundle/DataGridBundle/Resources/doc/backend/extensions/field_acl.md
@@ -1,7 +1,7 @@
 Field ACL extension
 ===================
 
-[Field ACL extension](../../../Extension/FieldAcl/FieldAclExtension.php) allows to check access to grid columns. Currently it is implemented only for ORM datasource.
+[Field ACL extension](../../../../Extension/FieldAcl/FieldAclExtension.php) allows to check access to grid columns. Currently it is implemented only for ORM datasource.
 
 To enable field ACL protection for a column, you should use `field_acl` section in a datagrid declaration:
 
diff --git a/src/Oro/Bundle/EmailBundle/DependencyInjection/Configuration.php b/src/Oro/Bundle/EmailBundle/DependencyInjection/Configuration.php
index 388c244aa28..dbe332aafc0 100644
--- a/src/Oro/Bundle/EmailBundle/DependencyInjection/Configuration.php
+++ b/src/Oro/Bundle/EmailBundle/DependencyInjection/Configuration.php
@@ -54,7 +54,8 @@ public function getConfigTreeBuilder()
                 'attachment_sync_enable' => ['value' => true],
                 'attachment_sync_max_size' => ['value' => 50],
                 'attachment_preview_limit' => ['value' => 8],
-                'sanitize_html' => ['value' => false]
+                'sanitize_html' => ['value' => false],
+                'threads_grouping' => ['value' => true]
             ]
         );
 
diff --git a/src/Oro/Bundle/EmailBundle/EventListener/Datagrid/EmailGridListener.php b/src/Oro/Bundle/EmailBundle/EventListener/Datagrid/EmailGridListener.php
index 1bc00e2aa9d..d4d658e7924 100644
--- a/src/Oro/Bundle/EmailBundle/EventListener/Datagrid/EmailGridListener.php
+++ b/src/Oro/Bundle/EmailBundle/EventListener/Datagrid/EmailGridListener.php
@@ -14,6 +14,7 @@
 use Oro\Bundle\DataGridBundle\Event\OrmResultBeforeQuery;
 use Oro\Bundle\EmailBundle\Datagrid\EmailQueryFactory;
 use Oro\Bundle\SecurityBundle\SecurityFacade;
+use Oro\Bundle\ConfigBundle\Config\ConfigManager;
 
 class EmailGridListener
 {
@@ -32,6 +33,11 @@ class EmailGridListener
      */
     protected $gridViewManager;
 
+    /**
+     * @var ConfigManager
+     */
+    protected $configManager;
+
     /**
      * Stores join's root and alias if joins for filters are added - ['eu' => ['alias1']]
      *
@@ -54,6 +60,14 @@ public function __construct(
         $this->gridViewManager = $gridViewManager;
     }
 
+    /**
+     * @param ConfigManager $configManager
+     */
+    public function setConfigManager(ConfigManager $configManager)
+    {
+        $this->configManager = $configManager;
+    }
+
     /**
      * @param OrmResultBeforeQuery $event
      */
@@ -92,6 +106,11 @@ public function onBuildAfter(BuildAfter $event)
             $queryBuilder->andWhere($queryBuilder->expr()->in('e.id', $emailIds));
         }
 
+        if ($this->configManager && $this->configManager->get('oro_email.threads_grouping')) {
+            $queryBuilder->andWhere('e.head = :enabled')->setParameter('enabled', true);
+            $countQb->andWhere('e.head = :enabled')->setParameter('enabled', true);
+        }
+
         $this->prepareQueryToFilter($parameters, $queryBuilder, $countQb);
     }
 
diff --git a/src/Oro/Bundle/EmailBundle/Resources/config/datagrid.yml b/src/Oro/Bundle/EmailBundle/Resources/config/datagrid.yml
index 854c99d5c28..da17864847a 100644
--- a/src/Oro/Bundle/EmailBundle/Resources/config/datagrid.yml
+++ b/src/Oro/Bundle/EmailBundle/Resources/config/datagrid.yml
@@ -193,15 +193,6 @@ datagrid:
 
     email-grid:
         extends: base-email-grid
-        source:
-            count_query:
-                where:
-                    and:
-                        - e.head = true
-            query:
-                where:
-                    and:
-                        - e.head = true
         # joins for filters to, cc, bcc, folders, folder and mailbox processes dynamically in
         # Oro\Bundle\EmailBundle\EventListener\Datagrid\EmailGridListener for performance reasons
         filters:
diff --git a/src/Oro/Bundle/EmailBundle/Resources/config/services.yml b/src/Oro/Bundle/EmailBundle/Resources/config/services.yml
index 2c6b8b88243..678b1078d31 100644
--- a/src/Oro/Bundle/EmailBundle/Resources/config/services.yml
+++ b/src/Oro/Bundle/EmailBundle/Resources/config/services.yml
@@ -568,6 +568,8 @@ services:
         tags:
             - { name: kernel.event_listener, event: oro_datagrid.datagrid.build.after.base-email-grid, method: onBuildAfter }
             - { name: kernel.event_listener, event: oro_datagrid.orm_datasource.result.before_query.base-email-grid, method: onResultBeforeQuery, priority: -255 }
+        calls:
+            - [setConfigManager, ['@oro_config.manager']]
 
     oro_email.listener.datagrid.activity:
         class: %oro_email.listener.datagrid.activity.class%
diff --git a/src/Oro/Bundle/EmailBundle/Resources/config/system_configuration.yml b/src/Oro/Bundle/EmailBundle/Resources/config/system_configuration.yml
index 06cfb36c835..09e6f4efd93 100644
--- a/src/Oro/Bundle/EmailBundle/Resources/config/system_configuration.yml
+++ b/src/Oro/Bundle/EmailBundle/Resources/config/system_configuration.yml
@@ -135,6 +135,15 @@ oro_system_configuration:
                 tooltip: oro.email.system_configuration.sanitize_html.tooltip
                 required: true
 
+        oro_email.threads_grouping:
+            data_type: boolean
+            type: choice
+            options:
+                label: oro.email.system_configuration.email_threads.use_threads.label
+                choices:
+                    - oro.email.system_configuration.email_threads.use_threads.choices.non_threaded.label
+                    - oro.email.system_configuration.email_threads.use_threads.choices.threaded.label
+
     tree:
         system_configuration:
             platform:
@@ -169,6 +178,9 @@ oro_system_configuration:
                                     mailboxes:
                                         children:
                                             - oro_email.mailbox_grid
+                                    email_threads:
+                                        children:
+                                            - oro_email.threads_grouping
         user_configuration:
             platform:
                 children:
@@ -191,6 +203,9 @@ oro_system_configuration:
                                     user_mailbox:
                                         children:
                                             - oro_email.user_mailbox
+                                    email_threads:
+                                        children:
+                                            - oro_email.threads_grouping
 
     api_tree:
         signature_configuration:
diff --git a/src/Oro/Bundle/EmailBundle/Resources/translations/messages.en.yml b/src/Oro/Bundle/EmailBundle/Resources/translations/messages.en.yml
index 57c389976bc..a0673273a90 100644
--- a/src/Oro/Bundle/EmailBundle/Resources/translations/messages.en.yml
+++ b/src/Oro/Bundle/EmailBundle/Resources/translations/messages.en.yml
@@ -51,6 +51,11 @@ oro:
 
             email_threads:
                 label: Email Threads
+                use_threads:
+                  label: Display email conversations as
+                  choices:
+                    non_threaded.label: Non-Threaded
+                    threaded.label: Threaded
 
             attachment_configuration:
                 label: Attachments
diff --git a/src/Oro/Bundle/EmailBundle/Resources/translations/validators.en.yml b/src/Oro/Bundle/EmailBundle/Resources/translations/validators.en.yml
index 1aa130a7b1e..0da88f9e0f5 100644
--- a/src/Oro/Bundle/EmailBundle/Resources/translations/validators.en.yml
+++ b/src/Oro/Bundle/EmailBundle/Resources/translations/validators.en.yml
@@ -1,3 +1,8 @@
 "The template for {{ field }} ({{ locale }}) has syntax error: {{ error }}": "The template for {{ field }} ({{ locale }}) has syntax error: {{ error }}"
 "This value contains not valid email address.": "This value contains not valid email address."
 "Recipient can not be empty": "Recipient can not be empty"
+
+oro:
+    email:
+        message:
+            mailbox_origin_constraint: At least one folder for sent emails is required. Make sure you clicked button "%button%" and there are some folders for incoming messages.
diff --git a/src/Oro/Bundle/EmailBundle/Resources/views/Email/Datagrid/Property/contacts.html.twig b/src/Oro/Bundle/EmailBundle/Resources/views/Email/Datagrid/Property/contacts.html.twig
index 4752ed49bc3..49557d64e25 100644
--- a/src/Oro/Bundle/EmailBundle/Resources/views/Email/Datagrid/Property/contacts.html.twig
+++ b/src/Oro/Bundle/EmailBundle/Resources/views/Email/Datagrid/Property/contacts.html.twig
@@ -38,7 +38,7 @@
             {{ EA.wrapTextToTag(firstLastRecipients, isNew) }}
         {% endif %}
 {% endif %}
-{% if threadEmailCount > 1 %}
+{% if oro_config_value('oro_email.threads_grouping') and threadEmailCount > 1 %}
     {{ EA.wrapTextToTag('(' ~ threadEmailCount ~ ')', isNew) }}
 {% endif %}
 </span>
diff --git a/src/Oro/Bundle/EmailBundle/Resources/views/Email/Thread/view.html.twig b/src/Oro/Bundle/EmailBundle/Resources/views/Email/Thread/view.html.twig
index 6b88c64a84d..f28601d970c 100644
--- a/src/Oro/Bundle/EmailBundle/Resources/views/Email/Thread/view.html.twig
+++ b/src/Oro/Bundle/EmailBundle/Resources/views/Email/Thread/view.html.twig
@@ -49,7 +49,8 @@
             {{ oro_widget_render({
                 'widgetType': 'block',
                 'wid': 'thread-view',
-                'url': path('oro_email_thread_widget', {'id': entity.id, 'renderContexts': false}),
+                'url': path('oro_email_thread_widget', {'id': entity.id, 'renderContexts': false,
+                    'showSingleEmail': not oro_config_value('oro_email.threads_grouping')}),
                 'alias': 'thread-view',
                 'contextsRendered': true
             }) }}
diff --git a/src/Oro/Bundle/EmailBundle/Validator/Constraints/MailboxOrigin.php b/src/Oro/Bundle/EmailBundle/Validator/Constraints/MailboxOrigin.php
index 9c5e1fbcc8a..f0c68d92fe8 100644
--- a/src/Oro/Bundle/EmailBundle/Validator/Constraints/MailboxOrigin.php
+++ b/src/Oro/Bundle/EmailBundle/Validator/Constraints/MailboxOrigin.php
@@ -7,8 +7,7 @@
 class MailboxOrigin extends Constraint
 {
     /** @var string */
-    public $message = 'At least one folder for sent emails is required. '
-        . 'Make sure you clicked button "%button%" and there are some folders for incoming messages.';
+    public $message = 'oro.email.message.mailbox_origin_constraint';
 
     /**
      * {@inheritdoc}
diff --git a/src/Oro/Bundle/LocaleBundle/Resources/public/js/formatter/address.js b/src/Oro/Bundle/LocaleBundle/Resources/public/js/formatter/address.js
index e4ec84de5fd..186b49065b2 100644
--- a/src/Oro/Bundle/LocaleBundle/Resources/public/js/formatter/address.js
+++ b/src/Oro/Bundle/LocaleBundle/Resources/public/js/formatter/address.js
@@ -37,7 +37,7 @@ define(['jquery', '../locale-settings', './name'
                 if ('name' === lowerCaseKey) {
                     value = nameFormatter.format(address, localeSettings.getCountryLocale(country));
                 } else if ('street' === lowerCaseKey) {
-                    value = address.street + ' ' + (address.street2 || '');
+                    value = (address.street || '') + ' ' + (address.street2 || '');
                 } else if ('street1' === lowerCaseKey) {
                     value = address.street;
                 } else {
diff --git a/src/Oro/Bundle/SecurityBundle/ORM/Walker/AclWalker.php b/src/Oro/Bundle/SecurityBundle/ORM/Walker/AclWalker.php
index 962bf9ff0b1..4a85fdf33f2 100644
--- a/src/Oro/Bundle/SecurityBundle/ORM/Walker/AclWalker.php
+++ b/src/Oro/Bundle/SecurityBundle/ORM/Walker/AclWalker.php
@@ -107,7 +107,6 @@ protected function processSubRequests(SelectStatement $AST, AclConditionStorage
         }
     }
 
-
     /**
      * @param ConditionalPrimary $factor
      * @param int                $factorId
@@ -125,7 +124,8 @@ protected function getSubSelectFromFactor(ConditionalPrimary $factor, $factorId,
                 ->conditionalFactors[$factorId]
                 ->simpleConditionalExpression
                 ->subselect;
-        } elseif (isset($factor->conditionalExpression->conditionalTerms)) {
+        } elseif (isset($factor->conditionalExpression->conditionalTerms)
+            && isset($factor->conditionalExpression->conditionalTerms[$factorId]->simpleConditionalExpression)) {
             $subSelect = $factor
                 ->conditionalExpression
                 ->conditionalTerms[$factorId]
@@ -204,7 +204,8 @@ protected function addAclToWhereClause($AST, array $whereConditions)
         $aclConditionalFactors = $this->aclConditionFactorBuilder->addWhereAclConditionalFactors(
             [], //default empty conditional factors
             $whereConditions,
-            $this->_getQuery()
+            $this->_getQuery(),
+            ['AST' => $AST]
         );
 
         if (!empty($aclConditionalFactors)) {