diff --git b/crm_core/contact/src/Tests/EventProcessingTest.php a/crm_core/contact/src/Tests/EventProcessingTest.php
new file mode 100644
index 0000000..8c859b6
--- /dev/null
+++ a/crm_core/contact/src/Tests/EventProcessingTest.php
@@ -0,0 +1,298 @@
+<?php
+/**
+ * @file
+ * Contains \Drupal\collect_crm_core_contact\Tests\EventProcessingTest.
+ */
+
+namespace Drupal\collect_crm_core_contact\Tests;
+
+use Drupal\collect\CollectContainerInterface;
+use Drupal\collect\Entity\Container;
+use Drupal\collect\Event\CollectEvent;
+use Drupal\crm_core_activity\Entity\Activity;
+use Drupal\crm_core_contact\Entity\Contact;
+use Drupal\crm_core_default_matching_engine\Entity\MatchingRule;
+use Drupal\simpletest\KernelTestBase;
+
+/**
+ * Tests the processing of contact form submission on integration level.
+ *
+ * @group collect
+ */
+class EventProcessingTest extends KernelTestBase {
+
+  /**
+   * Disabled config schema checking temporarily until all errors are resolved.
+   */
+  protected $strictConfigSchema = FALSE;
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = array(
+    'user',
+    'serialization',
+    'rest',
+    'hal',
+    'collect',
+    'field',
+    'text',
+    'datetime',
+    'entity',
+    'filter',
+    'entity_reference',
+    'crm_core_contact',
+    'crm_core_activity',
+    'crm_core_match',
+    'crm_core_default_matching_engine',
+    'collect_crm_core_contact',
+  );
+
+  /**
+   * Test json data.
+   *
+   * @var string
+   */
+  protected $json;
+
+  /**
+   * The submission to process.
+   *
+   * @var \Drupal\collect\CollectContainerInterface
+   */
+  protected $submission;
+
+  /**
+   * An existing contact.
+   *
+   * @var \Drupal\crm_core_contact\Entity\Contact
+   */
+  protected $contact;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $this->installEntitySchema('collect_container');
+    $this->installEntitySchema('crm_core_contact');
+    $this->installEntitySchema('crm_core_activity');
+    $this->installEntitySchema('user');
+
+    $this->installConfig(array(
+      'crm_core_contact',
+      'crm_core_activity',
+      'collect_crm_core_contact',
+    ));
+
+    \Drupal::configFactory()->getEditable('crm_core_match.engines')->set('default', array('status' => TRUE))->save();
+    /* @var \Drupal\crm_core_default_matching_engine\Entity\MatchingRule $rule */
+    $rule = MatchingRule::load('individual');
+    $rule->setStatus(TRUE);
+    $rule->threshold = 8;
+    $rule->rules = array(
+      'contact_remote_id' => array(
+        'value' => array(
+          'status' => '1',
+          'operator' => '=',
+          'options' => '',
+          'score' => '10',
+          'weight' => '0',
+        ),
+      ),
+      'contact_mail' => array(
+        'value' => array(
+          'status' => '1',
+          'operator' => '=',
+          'options' => '',
+          'score' => '9',
+          'weight' => '0',
+        ),
+      ),
+    );
+    $rule->save();
+
+    $this->json = file_get_contents(__DIR__ . '/../../tests/src/Unit/fixture.json');
+    $this->submission = Container::create(array(
+      'origin_uri' => 'http://localhost/entity/message/feedback/2494b3ba-158b-4066-9833-510bd72c82eb',
+      'date' => REQUEST_TIME,
+      'data' => array(
+        'data' => $this->json,
+        'type' => 'application/json',
+        'schema' => 'https://drupal.org/project/collect_client/contact',
+      ),
+    ));
+    $this->submission->save();
+
+    $this->contact = Contact::create(array(
+      'type' => 'individual',
+      'name' => 'Aenean Risus',
+      'contact_mail' => 'anean@example.com',
+    ));
+    $this->contact->save();
+  }
+
+  /**
+   * Tests submission containing a user that does not match an existing contact.
+   */
+  public function testWithUserWithoutMatch() {
+    $this->triggerProcessing($this->submission);
+
+    $contact = Contact::load(2);
+    $this->assertNewUserContact($contact);
+
+    $activity = Activity::load(1);
+    $this->assertActivity($activity, $contact);
+  }
+
+  /**
+   * Tests submission containing a user that does match an existing contact.
+   */
+  public function testWithUserWithMatch() {
+    $this->contact->set('contact_remote_id', 'http://example.com/user/1');
+    $this->contact->save();
+
+    $this->triggerProcessing($this->submission);
+
+    $contact = Contact::load(2);
+    $this->assertNull($contact, 'No new contact was created.');
+
+    $contact = Contact::load(1);
+    $this->assertMatchContact($contact);
+    $activity = Activity::load(1);
+    $this->assertActivity($activity, $contact);
+  }
+
+  /**
+   * Tests submission not containing a user not matching an existing contact.
+   */
+  public function testWithoutUserWithoutMatch() {
+    $this->unsetUser();
+
+    $this->triggerProcessing($this->submission);
+
+    $contact = Contact::load(2);
+    $this->assertNewMessageContact($contact);
+    $activity = Activity::load(1);
+    $this->assertActivity($activity, $contact);
+  }
+
+  /**
+   * Tests submission not containing a user that does match an existing contact.
+   */
+  public function testWithoutUserWithMatch() {
+    $this->unsetUser();
+    $data = json_decode($this->json, TRUE);
+    $data['values']['mail'][0]['value'] = 'anean@example.com';
+    $this->json = json_encode($data);
+    $this->submission->setData($this->json);
+
+    $this->triggerProcessing($this->submission);
+
+    $contact = Contact::load(2);
+    $this->assertNull($contact, 'No new contact was created.');
+
+    $contact = Contact::load(1);
+    $this->assertMatchContact($contact);
+    $activity = Activity::load(1);
+    $this->assertActivity($activity, $contact);
+  }
+
+  /**
+   * Asserts an activity.
+   *
+   * An activity was created with values from the submission and linked to the
+   * container and contact
+   *
+   * @param Activity $activity
+   *   The activity to assert.
+   * @param Contact $contact
+   *   The contact expected to be linked with the activity.
+   */
+  protected function assertActivity(Activity $activity = NULL, Contact $contact = NULL) {
+    $this->assertNotNull($activity, 'New activity was created.');
+    if ($activity) {
+      $this->assertEqual('Aenean lacinia bibendum nulla sed consectetur', $activity->get('title')->value, 'Found expected activity title');
+      $data = json_decode($this->json, TRUE);
+      $this->assertEqual($data['values']['message'][0]['value'], $activity->get('activity_notes')->value, 'Found expected activity title');
+      if ($contact) {
+        $this->assertEqual($contact->id(), $activity->get('activity_participants')->target_id, 'Activity was assigned to the expected contact');
+      }
+      $this->assertEqual($this->submission->id(), $activity->get('activity_submission')->target_id, 'Activity was linked to the container record');
+      $this->assertNotNull($activity->get('activity_date')->value, 'Activity has date set');
+    }
+  }
+
+  /**
+   * Asserts a new user contact.
+   *
+   * A new contact was created with values from the user section of the
+   * submission.
+   *
+   * @param Contact $contact
+   *   The contact to assert.
+   */
+  protected function assertNewUserContact(Contact $contact = NULL) {
+    $this->assertNotNull($contact, 'New contact was created.');
+    if ($contact) {
+      $this->assertEqual('dapibus', $contact->get('name')->value, 'Contact is named \'dapibus\'');
+      $this->assertEqual('dapibus@example.com', $contact->get('contact_mail')->value, 'Contact mail is \'dapibus@example.com\'');
+      $this->assertEqual('http://example.com/user/1', $contact->get('contact_remote_id')->value, 'Remote identifier is \'http://example.com/user/1\'');
+    }
+  }
+
+  /**
+   * Asserts a new message contact.
+   *
+   * A new contact was created with values from the message part of the
+   * submission.
+   *
+   * @param Contact $contact
+   *   The contact to assert.
+   */
+  protected function assertNewMessageContact(Contact $contact = NULL) {
+    $this->assertNotNull($contact, 'New contact was created.');
+    if ($contact) {
+      $this->assertEqual('Ullamcorper Fermentum', $contact->get('name')->value, 'Contact is named \'Ullamcorper Fermentum\'');
+      $this->assertEqual('ullamcorper@example.com', $contact->get('contact_mail')->value, 'Contact mail is \'ullamcorper@example.com\'');
+      $this->assertNull($contact->get('contact_remote_id')->value, 'Remote identifier is undefined');
+    }
+  }
+
+  /**
+   * Asserts the value of a contact identified as a match.
+   *
+   * The existing contact was not overwritten.
+   *
+   * @param Contact $contact
+   *   The contact to assert.
+   */
+  protected function assertMatchContact(Contact $contact) {
+    $this->assertEqual('Aenean Risus', $contact->get('name')->value, 'Contact is named \'Aenean Risus\'');
+    $this->assertEqual('anean@example.com', $contact->get('contact_mail')->value, 'Contact mail is \'anean@example.com\'');
+  }
+
+  /**
+   * Triggers processing.
+   *
+   * @param \Drupal\collect\CollectContainerInterface $submission
+   *   The submission to be processed.
+   */
+  protected function triggerProcessing(CollectContainerInterface $submission) {
+    $event = new CollectEvent($submission);
+    /* @var \Symfony\Component\EventDispatcher\EventDispatcherInterface $dispatcher */
+    $dispatcher = $this->container->get('event_dispatcher');
+    $dispatcher->dispatch(CollectEvent::NAME, $event);
+  }
+
+  /**
+   * Sets the user to null in the submission data.
+   */
+  protected function unsetUser() {
+    $data = json_decode($this->json, TRUE);
+    $data['user'] = NULL;
+    $this->json = json_encode($data);
+    $this->submission->setData($this->json);
+  }
+}