diff --git a/config/install/inmail.fetcher.imap.yml b/config/install/inmail.fetcher.imap.yml
deleted file mode 100644
index a460cff..0000000
--- a/config/install/inmail.fetcher.imap.yml
+++ /dev/null
@@ -1,9 +0,0 @@
-id: imap
-label: 'IMAP Sample'
-plugin: imap
-configuration:
-  host:
-  ssl: FALSE
-  port: 143
-  username:
-  password:
diff --git a/config/schema/inmail.schema.yml b/config/schema/inmail.schema.yml
index c6cb02a..fff1678 100644
--- a/config/schema/inmail.schema.yml
+++ b/config/schema/inmail.schema.yml
@@ -45,8 +45,8 @@ inmail.inmail_handler.*:
       label: 'Configuration'
       type: inmail.handler.[%parent.plugin]
 
-inmail.fetcher.*:
-  label: 'Mail fetcher'
+inmail.deliverer.*:
+  label: 'Mail deliverer'
   type: config_entity
   mapping:
     id:
@@ -60,7 +60,7 @@ inmail.fetcher.*:
       type: string
     configuration:
       label: 'Configuration'
-      type: inmail.plugin.fetcher.[%parent.plugin]
+      type: inmail.plugin.deliverer.[%parent.plugin]
 
 # Empty default configuration schema
 inmail.analyzer.*:
@@ -80,8 +80,8 @@ inmail.handler.moderator_forward:
       label: 'Moderator address'
       type: email
 
-inmail.plugin.fetcher.imap:
-  label: 'IMAP Fetcher'
+inmail.plugin.deliverer.imap:
+  label: 'IMAP Deliverer'
   type: mapping
   mapping:
     host:
diff --git a/inmail.links.action.yml b/inmail.links.action.yml
new file mode 100644
index 0000000..255b82b
--- /dev/null
+++ b/inmail.links.action.yml
@@ -0,0 +1,5 @@
+inmail.deliverer_add:
+  route_name: inmail.deliverer_add
+  title: 'Configure new deliverer'
+  appears_on:
+    - 'inmail.deliverer_list'
diff --git a/inmail.links.task.yml b/inmail.links.task.yml
index d835d19..7f7b939 100644
--- a/inmail.links.task.yml
+++ b/inmail.links.task.yml
@@ -4,9 +4,9 @@ inmail.settings:
   base_route: inmail.settings
   weight: 0
 
-inmail.fetcher_list:
-  route_name: inmail.fetcher_list
-  title: 'Mail fetchers'
+inmail.deliverer_list:
+  route_name: inmail.deliverer_list
+  title: 'Mail deliverers'
   base_route: inmail.settings
   weight: 1
 
diff --git a/inmail.module b/inmail.module
index 862a8b5..b2d76a8 100644
--- a/inmail.module
+++ b/inmail.module
@@ -17,7 +17,7 @@ use Drupal\inmail\Entity\AnalyzerConfig;
  * You can read more under the following chapters:
  *   - @link processing The general message processing flow @endlink
  *   - @link mime Message parsing @endlink
- *   - @link fetching Fetching email over IMAP @endlink
+ *   - @link deliverer Fetching email over IMAP @endlink
  *   - @link analyzer Analysis of new messages @endlink
  *   - @link handler Handling analyzed messages @endlink
  *   - @link mailmute Integration with the Mailmute module @enlink
@@ -93,11 +93,12 @@ use Drupal\inmail\Entity\AnalyzerConfig;
  */
 
 /**
- * @defgroup fetching Fetching email over IMAP
+ * @defgroup deliverer Fetching email over IMAP
  * @{
- * To process messages from an IMAP account, enter server details and
- * credentials on the Inmail settings form. Messages are fetched and processed
- * during Cron runs.
+ * To process messages from an IMAP account, visit the "Mail deliverers" list
+ * (admin/config/inmail/deliverers) and configure a new deliverer, entering
+ * server details and credentials in the form. Messages are delivered and
+ * processed during Cron runs.
  * @}
  */
 
@@ -270,18 +271,18 @@ function inmail_mail($key, &$message, $params) {
  * Implements hook_cron().
  */
 function inmail_cron() {
-  /** @var \Drupal\inmail\Entity\FetcherConfig[] $fetchers */
-  $fetchers = \Drupal::entityManager()->getStorage('inmail_fetcher')->loadMultiple();
-  /** @var \Drupal\Component\Plugin\PluginManagerInterface $fetcher_manager */
-  $fetcher_manager = \Drupal::service('plugin.manager.inmail.fetcher');
+  /** @var \Drupal\inmail\Entity\DelivererConfig[] $deliverers */
+  $deliverers = \Drupal::entityManager()->getStorage('inmail_deliverer')->loadMultiple();
+  /** @var \Drupal\Component\Plugin\PluginManagerInterface $deliverer_manager */
+  $deliverer_manager = \Drupal::service('plugin.manager.inmail.deliverer');
   /** @var \Drupal\inmail\MessageProcessorInterface $processor */
   $processor = \Drupal::service('inmail.processor');
 
   // Fetch and process new mail.
-  foreach ($fetchers as $fetcher) {
-    /** @var \Drupal\inmail\Plugin\inmail\Fetcher\FetcherInterface $plugin */
-    $plugin = $fetcher_manager->createInstance($fetcher->id(), $fetcher->getConfiguration());
-    $raws = $plugin->fetch();
+  foreach ($deliverers as $deliverer) {
+    /** @var \Drupal\inmail\Plugin\inmail\Deliverer\DelivererInterface $plugin */
+    $plugin = $deliverer_manager->createInstance($deliverer->id(), $deliverer->getConfiguration());
+    $raws = $plugin->deliver();
     $processor->processMultiple($raws);
   }
 }
diff --git a/inmail.routing.yml b/inmail.routing.yml
index d7d0ab8..aa9de00 100644
--- a/inmail.routing.yml
+++ b/inmail.routing.yml
@@ -66,32 +66,40 @@ entity.inmail_handler.disable:
   requirements:
     _permission: 'administer inmail'
 
-inmail.fetcher_list:
-  path: admin/config/system/inmail/fetchers
+inmail.deliverer_list:
+  path: admin/config/system/inmail/deliverers
   defaults:
-    _entity_list: 'inmail_fetcher'
-    _title: 'Mail fetchers'
+    _entity_list: 'inmail_deliverer'
+    _title: 'Mail deliverers'
   requirements:
     _permission: 'administer inmail'
 
-entity.inmail_fetcher.edit_form:
-  path: admin/config/system/inmail/fetchers/{inmail_fetcher}
+inmail.deliverer_add:
+  path: admin/config/system/inmail/deliverers/add
   defaults:
-    _entity_form: 'inmail_fetcher.default'
-    _title_callback: \Drupal\inmail\Controller\FetcherController::titleEdit
+    _entity_form: 'inmail_deliverer.add'
+    _title: 'Configure new deliverer'
   requirements:
     _permission: 'administer inmail'
 
-entity.inmail_fetcher.enable:
-  path: admin/config/system/inmail/fetchers/{inmail_fetcher}/enable
+entity.inmail_deliverer.edit_form:
+  path: admin/config/system/inmail/deliverers/{inmail_deliverer}
   defaults:
-    _controller: \Drupal\inmail\Controller\FetcherController::enable
+    _entity_form: 'inmail_deliverer.default'
+    _title_callback: \Drupal\inmail\Controller\DelivererController::titleEdit
   requirements:
     _permission: 'administer inmail'
 
-entity.inmail_fetcher.disable:
-  path: admin/config/system/inmail/fetchers/{inmail_fetcher}/disable
+entity.inmail_deliverer.enable:
+  path: admin/config/system/inmail/deliverers/{inmail_deliverer}/enable
   defaults:
-    _controller: \Drupal\inmail\Controller\FetcherController::disable
+    _controller: \Drupal\inmail\Controller\DelivererController::enable
+  requirements:
+    _permission: 'administer inmail'
+
+entity.inmail_deliverer.disable:
+  path: admin/config/system/inmail/deliverers/{inmail_deliverer}/disable
+  defaults:
+    _controller: \Drupal\inmail\Controller\DelivererController::disable
   requirements:
     _permission: 'administer inmail'
diff --git a/inmail.services.yml b/inmail.services.yml
index 260e421..863b9ac 100644
--- a/inmail.services.yml
+++ b/inmail.services.yml
@@ -2,14 +2,14 @@ services:
   inmail.processor:
     class: Drupal\inmail\MessageProcessor
     arguments: ['@entity.manager', '@plugin.manager.inmail.analyzer', '@plugin.manager.inmail.handler', '@logger.channel.inmail']
-  plugin.manager.inmail.fetcher:
+  plugin.manager.inmail.deliverer:
     class: Drupal\Core\Plugin\DefaultPluginManager
     arguments:
-      - 'Plugin/inmail/Fetcher'
+      - 'Plugin/inmail/Deliverer'
       - '@container.namespaces'
       - '@module_handler'
-      - 'Drupal\inmail\Plugin\inmail\Fetcher\FetcherInterface'
-      - 'Drupal\inmail\Annotation\Fetcher'
+      - 'Drupal\inmail\Plugin\inmail\Deliverer\DelivererInterface'
+      - 'Drupal\inmail\Annotation\Deliverer'
   plugin.manager.inmail.analyzer:
     class: Drupal\inmail\AnalyzerManager
     parent: default_plugin_manager
diff --git a/inmail_collect/src/Plugin/inmail/Handler/CollectHandler.php b/inmail_collect/src/Plugin/inmail/Handler/CollectHandler.php
index 235ed05..ddab6d5 100644
--- a/inmail_collect/src/Plugin/inmail/Handler/CollectHandler.php
+++ b/inmail_collect/src/Plugin/inmail/Handler/CollectHandler.php
@@ -71,7 +71,7 @@ class CollectHandler extends HandlerBase {
       'header-from' => $message->getHeader()->getFieldBody('From'),
       'header-message-id' => $message->getHeader()->getFieldBody('Message-Id'),
       'raw' => $message->toString(),
-      // @todo Add fetcher reference here. Relevant if multiple present.
+      // @todo Add deliverer reference here. Relevant if multiple present.
     );
 
     Container::create(array(
diff --git a/src/Annotation/Fetcher.php b/src/Annotation/Deliverer.php
similarity index 51%
rename from src/Annotation/Fetcher.php
rename to src/Annotation/Deliverer.php
index f42a749..8beda56 100644
--- a/src/Annotation/Fetcher.php
+++ b/src/Annotation/Deliverer.php
@@ -1,7 +1,7 @@
 <?php
 /**
  * @file
- * Contains \Drupal\inmail\Annotation\Fetcher.
+ * Contains \Drupal\inmail\Annotation\Deliverer.
  */
 
 namespace Drupal\inmail\Annotation;
@@ -9,23 +9,23 @@ namespace Drupal\inmail\Annotation;
 use Drupal\Component\Annotation\Plugin;
 
 /**
- * Defines the plugin annotation of a mail fetcher.
+ * Defines the plugin annotation of a mail deliverer.
  *
- * @ingroup fetching
+ * @ingroup deliverer
  *
  * @Annotation
  */
-class Fetcher extends Plugin {
+class Deliverer extends Plugin {
 
   /**
-   * The short machine-name to uniquely identify the fetcher.
+   * The short machine-name to uniquely identify the deliverer.
    *
    * @var string
    */
   protected $id;
 
   /**
-   * The display label of the fetcher.
+   * The display label of the deliverer.
    *
    * @var \Drupal\Core\StringTranslation\TranslationWrapper
    */
diff --git a/src/Controller/FetcherController.php b/src/Controller/DelivererController.php
similarity index 28%
rename from src/Controller/FetcherController.php
rename to src/Controller/DelivererController.php
index 8018524..fe71948 100644
--- a/src/Controller/FetcherController.php
+++ b/src/Controller/DelivererController.php
@@ -1,51 +1,51 @@
 <?php
 /**
  * @file
- * Contains \Drupal\inmail\Controller\FetcherController.
+ * Contains \Drupal\inmail\Controller\DelivererController.
  */
 
 namespace Drupal\inmail\Controller;
 
 use Drupal\Core\Controller\ControllerBase;
-use Drupal\inmail\Entity\FetcherConfig;
+use Drupal\inmail\Entity\DelivererConfig;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpFoundation\RedirectResponse;
 
 /**
- * Route controller for mail fetchers.
+ * Route controller for mail deliverers.
  *
- * @ingroup fetching
+ * @ingroup deliverer
  */
-class FetcherController extends ControllerBase {
+class DelivererController extends ControllerBase {
 
   /**
    * {@inheritdoc}
    */
   public static function create(ContainerInterface $container) {
-    return new static($container->get('plugin.manager.inmail.fetcher'));
+    return new static($container->get('plugin.manager.inmail.deliverer'));
   }
 
   /**
-   * Returns a title for the fetcher configuration edit page.
+   * Returns a title for the deliverer configuration edit page.
    */
-  public function titleEdit(FetcherConfig $inmail_fetcher) {
-    return $this->t('Configure %label fetcher', array('%label' => $inmail_fetcher->label()));
+  public function titleEdit(DelivererConfig $inmail_deliverer) {
+    return $this->t('Configure deliverer %label', array('%label' => $inmail_deliverer->label()));
   }
 
   /**
-   * Enables a mail fetcher.
+   * Enables a mail deliverer.
    */
-  public function enable(FetcherConfig $inmail_fetcher) {
-    $inmail_fetcher->enable()->save();
-    return new RedirectResponse(\Drupal::url('inmail.fetcher_list', [], ['absolute' => TRUE]));
+  public function enable(DelivererConfig $inmail_deliverer) {
+    $inmail_deliverer->enable()->save();
+    return new RedirectResponse(\Drupal::url('inmail.deliverer_list', [], ['absolute' => TRUE]));
   }
 
   /**
-   * Disables a mail fetcher.
+   * Disables a mail deliverer.
    */
-  public function disable(FetcherConfig $inmail_fetcher) {
-    $inmail_fetcher->disable()->save();
-    return new RedirectResponse(\Drupal::url('inmail.fetcher_list', [], ['absolute' => TRUE]));
+  public function disable(DelivererConfig $inmail_deliverer) {
+    $inmail_deliverer->disable()->save();
+    return new RedirectResponse(\Drupal::url('inmail.deliverer_list', [], ['absolute' => TRUE]));
   }
 
 }
diff --git a/src/FetcherListBuilder.php b/src/DelivererListBuilder.php
similarity index 67%
rename from src/FetcherListBuilder.php
rename to src/DelivererListBuilder.php
index a45a41d..c01b317 100644
--- a/src/FetcherListBuilder.php
+++ b/src/DelivererListBuilder.php
@@ -1,7 +1,7 @@
 <?php
 /**
  * @file
- * Contains \Drupal\inmail\FetcherListBuilder.
+ * Contains \Drupal\inmail\DelivererListBuilder.
  */
 
 namespace Drupal\inmail;
@@ -14,27 +14,25 @@ use Drupal\Core\Entity\EntityTypeInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
- * List builder for message fetcher configurations.
+ * List builder for message deliverer configurations.
  *
- * @todo Add "Configure new fetcher" action button.
- *
- * @ingroup fetching
+ * @ingroup deliverer
  */
-class FetcherListBuilder extends ConfigEntityListBuilder {
+class DelivererListBuilder extends ConfigEntityListBuilder {
 
   /**
-   * The mail fetcher plugin manager.
+   * The mail deliverer plugin manager.
    *
    * @var \Drupal\Component\Plugin\PluginManagerInterface
    */
-  protected $fetcherManager;
+  protected $delivererManager;
 
   /**
-   * Constructs a new FetcherListBuilder.
+   * Constructs a new DelivererListBuilder.
    */
-  public function __construct(EntityTypeInterface $entity_type, EntityStorageInterface $storage, PluginManagerInterface $fetcher_manager) {
+  public function __construct(EntityTypeInterface $entity_type, EntityStorageInterface $storage, PluginManagerInterface $deliverer_manager) {
     parent::__construct($entity_type, $storage);
-    $this->fetcherManager = $fetcher_manager;
+    $this->delivererManager = $deliverer_manager;
   }
 
   /**
@@ -44,7 +42,7 @@ class FetcherListBuilder extends ConfigEntityListBuilder {
     return new static(
       $entity_type,
       $container->get('entity.manager')->getStorage($entity_type->id()),
-      $container->get('plugin.manager.inmail.fetcher')
+      $container->get('plugin.manager.inmail.deliverer')
     );
   }
 
@@ -52,7 +50,7 @@ class FetcherListBuilder extends ConfigEntityListBuilder {
    * {@inheritdoc}
    */
   public function buildHeader() {
-    $row['label'] = $this->t('Fetcher');
+    $row['label'] = $this->t('Deliverer');
     $row['plugin'] = $this->t('Plugin');
     return $row + parent::buildHeader();
   }
@@ -61,10 +59,10 @@ class FetcherListBuilder extends ConfigEntityListBuilder {
    * {@inheritdoc}
    */
   public function buildRow(EntityInterface $entity) {
-    /** @var \Drupal\inmail\Entity\FetcherConfig $entity */
+    /** @var \Drupal\inmail\Entity\DelivererConfig $entity */
     $plugin_id = $entity->getPluginId();
-    if ($this->fetcherManager->hasDefinition($plugin_id)) {
-      $plugin_label = $this->fetcherManager->getDefinition($plugin_id)['label'];
+    if ($this->delivererManager->hasDefinition($plugin_id)) {
+      $plugin_label = $this->delivererManager->getDefinition($plugin_id)['label'];
     }
     else {
       $plugin_label = $this->t('Plugin missing');
diff --git a/src/Entity/FetcherConfig.php b/src/Entity/DelivererConfig.php
similarity index 33%
rename from src/Entity/FetcherConfig.php
rename to src/Entity/DelivererConfig.php
index c67d3a2..cee6152 100644
--- a/src/Entity/FetcherConfig.php
+++ b/src/Entity/DelivererConfig.php
@@ -1,26 +1,27 @@
 <?php
 /**
  * @file
- * Contains \Drupal\inmail\Entity\FetcherConfig.
+ * Contains \Drupal\inmail\Entity\DelivererConfig.
  */
 
 namespace Drupal\inmail\Entity;
 
 /**
- * Mail fetcher configuration entity.
+ * Mail deliverer configuration entity.
  *
- * @ingroup fetching
+ * @ingroup deliverer
  *
  * @ConfigEntityType(
- *   id = "inmail_fetcher",
- *   label = @Translation("Mail fetcher"),
+ *   id = "inmail_deliverer",
+ *   label = @Translation("Mail deliverer"),
  *   admin_permission = "administer inmail",
- *   config_prefix = "fetcher",
+ *   config_prefix = "deliverer",
  *   handlers = {
  *     "form" = {
- *       "default" = "Drupal\inmail\Form\FetcherConfigurationForm"
+ *       "default" = "Drupal\inmail\Form\DelivererConfigurationForm",
+ *       "add" = "Drupal\inmail\Form\DelivererConfigurationForm"
  *     },
- *     "list_builder" = "Drupal\inmail\FetcherListBuilder"
+ *     "list_builder" = "Drupal\inmail\DelivererListBuilder"
  *   },
  *   entity_keys = {
  *     "id" = "id",
@@ -28,11 +29,11 @@ namespace Drupal\inmail\Entity;
  *     "status" = "status"
  *   },
  *   links = {
- *     "edit-form" = "entity.inmail_fetcher.edit_form",
- *     "enable" = "entity.inmail_fetcher.enable",
- *     "disable" = "entity.inmail_fetcher.disable"
+ *     "edit-form" = "entity.inmail_deliverer.edit_form",
+ *     "enable" = "entity.inmail_deliverer.enable",
+ *     "disable" = "entity.inmail_deliverer.disable"
  *   }
  * )
  */
-class FetcherConfig extends PluginConfigEntity {
+class DelivererConfig extends PluginConfigEntity {
 }
diff --git a/src/Form/FetcherConfigurationForm.php b/src/Form/DelivererConfigurationForm.php
similarity index 58%
rename from src/Form/FetcherConfigurationForm.php
rename to src/Form/DelivererConfigurationForm.php
index e2972ef..e04f37e 100644
--- a/src/Form/FetcherConfigurationForm.php
+++ b/src/Form/DelivererConfigurationForm.php
@@ -1,7 +1,7 @@
 <?php
 /**
  * @file
- * Contains \Drupal\inmail\Form\FetcherConfigurationForm.
+ * Contains \Drupal\inmail\Form\DelivererConfigurationForm.
  */
 
 namespace Drupal\inmail\Form;
@@ -10,23 +10,23 @@ use Drupal\Core\Form\FormStateInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
- * Configuration form for fetchers.
+ * Configuration form for deliverers.
  *
- * Fetcher plugins that inherit
+ * Deliverer plugins that inherit
  * \Drupal\Component\Plugin\ConfigurablePluginInterface may specify
  * plugin-specific configuration.
  *
- * @ingroup fetching
+ * @ingroup deliverer
  */
-class FetcherConfigurationForm extends PluginConfigurationForm {
+class DelivererConfigurationForm extends PluginConfigurationForm {
 
   /**
    * {@inheritdoc}
    */
   public static function create(ContainerInterface $container) {
     return new static(
-      $container->get('plugin.manager.inmail.fetcher'),
-      $container->get('entity.manager')->getStorage('inmail_fetcher')
+      $container->get('plugin.manager.inmail.deliverer'),
+      $container->get('entity.manager')->getStorage('inmail_deliverer')
     );
   }
 
@@ -36,7 +36,7 @@ class FetcherConfigurationForm extends PluginConfigurationForm {
   public function submitForm(array &$form, FormStateInterface $form_state) {
     parent::submitForm($form, $form_state);
 
-    $form_state->setRedirect('inmail.fetcher_list');
+    $form_state->setRedirect('inmail.deliverer_list');
   }
 
 }
diff --git a/src/Form/PluginConfigurationForm.php b/src/Form/PluginConfigurationForm.php
index 3be2bcc..2da3b02 100644
--- a/src/Form/PluginConfigurationForm.php
+++ b/src/Form/PluginConfigurationForm.php
@@ -46,15 +46,11 @@ class PluginConfigurationForm extends EntityForm {
     /** @var \Drupal\inmail\Entity\PluginConfigEntity $entity */
     $entity = $this->getEntity();
 
-    // Load plugin instance.
-    /** @var \Drupal\Core\Plugin\PluginFormInterface $plugin */
-    $plugin = $this->pluginManager->createInstance($entity->getPluginId(), $entity->getConfiguration());
-    $form_state->set('plugin', $plugin);
-
     $form['label'] = array(
       '#title' => $this->t('Label'),
       '#type' => 'textfield',
       '#default_value' => $entity->label(),
+      '#required' => TRUE,
     );
 
     $form['id'] = array(
@@ -72,7 +68,46 @@ class PluginConfigurationForm extends EntityForm {
       '#default_value' => TRUE,
     );
 
-    $form['configuration'] = $plugin->buildConfigurationForm(array(), $form_state);
+    $form['plugin_container'] = array(
+      '#type' => 'container',
+      '#prefix' => '<div id="inmail-plugin">',
+      '#suffix' => '</div>',
+    );
+
+    // Unless editing an existing plugin config, show plugin select field.
+    if ($entity->isNew()) {
+      $form['plugin_container']['plugin'] = array(
+        '#type' => 'select',
+        '#title' => $this->t('Plugin'),
+        '#options' => array_map(function(array $plugin_definition) {
+          return $plugin_definition['label'];
+        }, $this->pluginManager->getDefinitions()),
+        '#default_value' => $entity->getPluginId(),
+        '#required' => TRUE,
+        '#ajax' => array(
+          'callback' => '::getPluginContainerFormChild',
+          'wrapper' => 'inmail-plugin',
+        ),
+        '#submit' => array('::submitSelectPlugin'),
+        '#executes_submit_callback' => TRUE,
+        '#limit_validation_errors' => array(array('plugin')),
+      );
+
+      $form['plugin_container']['plugin_submit'] = array(
+        '#type' => 'submit',
+        '#value' => $this->t('Select plugin'),
+        '#submit' => array('::submitSelectPlugin'),
+        '#attributes' => array('class' => array('js-hide')),
+      );
+    }
+
+    // Load plugin instance and form.
+    /** @var \Drupal\Core\Plugin\PluginFormInterface $plugin */
+    if ($entity->getPluginId()) {
+      $plugin = $this->pluginManager->createInstance($entity->getPluginId(), $entity->getConfiguration());
+      $form_state->set('plugin', $plugin);
+      $form['plugin_container']['configuration'] = $plugin->buildConfigurationForm(array(), $form_state);
+    }
 
     return $form;
   }
@@ -91,14 +126,43 @@ class PluginConfigurationForm extends EntityForm {
   }
 
   /**
+   * Submit handler for plugin selection.
+   *
+   * @param array $form
+   *   The form structure.
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The form state.
+   */
+  public function submitSelectPlugin(array $form, FormStateInterface $form_state) {
+    $this->entity = $this->buildEntity($form, $form_state);
+    $form_state->setRebuild();
+  }
+
+  /**
+   * Ajax callback returning the plugin_container part of the form.
+   *
+   * @param array $form
+   *   The form structure.
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The form state.
+   *
+   * @return array
+   *   The plugin_container form part.
+   */
+  public function getPluginContainerFormChild(array $form, FormStateInterface $form_state) {
+    return $form['plugin_container'];
+  }
+
+  /**
    * {@inheritdoc}
    */
   public function validateForm(array &$form, FormStateInterface $form_state) {
     parent::validateForm($form, $form_state);
 
     /** @var \Drupal\Core\Plugin\PluginFormInterface $plugin */
-    $plugin = $form_state->get('plugin');
-    $plugin->validateConfigurationForm($form, $form_state);
+    if ($plugin = $form_state->get('plugin')) {
+      $plugin->validateConfigurationForm($form, $form_state);
+    }
   }
 
   /**
@@ -109,8 +173,9 @@ class PluginConfigurationForm extends EntityForm {
 
     // Let the plugin update its configuration from the form.
     /** @var \Drupal\Core\Plugin\PluginFormInterface|\Drupal\Component\Plugin\ConfigurablePluginInterface $plugin */
-    $plugin = $form_state->get('plugin');
-    $plugin->submitConfigurationForm($form, $form_state);
+    if ($plugin = $form_state->get('plugin')) {
+      $plugin->submitConfigurationForm($form, $form_state);
+    }
 
     // Copy plugin configuration to the entity for persistence. The reason for
     // not doing this by overriding copyFormValuesToEntity is that the plugin
diff --git a/src/Plugin/inmail/Fetcher/FetcherBase.php b/src/Plugin/inmail/Deliverer/DelivererBase.php
similarity index 81%
rename from src/Plugin/inmail/Fetcher/FetcherBase.php
rename to src/Plugin/inmail/Deliverer/DelivererBase.php
index b39d44e..6eed7c4 100644
--- a/src/Plugin/inmail/Fetcher/FetcherBase.php
+++ b/src/Plugin/inmail/Deliverer/DelivererBase.php
@@ -1,23 +1,23 @@
 <?php
 /**
  * @file
- * Contains \Plugin\inmail\Fetcher\FetcherBase.
+ * Contains \Plugin\inmail\Deliverer\DelivererBase.
  */
 
-namespace Drupal\inmail\Plugin\inmail\Fetcher;
+namespace Drupal\inmail\Plugin\inmail\Deliverer;
 
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Plugin\PluginBase;
 
 /**
- * Base class for mail fetchers.
+ * Base class for mail deliverers.
  *
- * This provides dumb implementations for most methods, but leaves ::fetch()
+ * This provides dumb implementations for most methods, but leaves ::deliver()
  * abstract.
  *
- * @ingroup fetching
+ * @ingroup deliverer
  */
-abstract class FetcherBase extends PluginBase implements FetcherInterface {
+abstract class DelivererBase extends PluginBase implements DelivererInterface {
 
   /**
    * {@inheritdoc}
diff --git a/src/Plugin/inmail/Fetcher/FetcherInterface.php b/src/Plugin/inmail/Deliverer/DelivererInterface.php
similarity index 41%
rename from src/Plugin/inmail/Fetcher/FetcherInterface.php
rename to src/Plugin/inmail/Deliverer/DelivererInterface.php
index 3cabede..c90ded9 100644
--- a/src/Plugin/inmail/Fetcher/FetcherInterface.php
+++ b/src/Plugin/inmail/Deliverer/DelivererInterface.php
@@ -1,36 +1,36 @@
 <?php
 /**
  * @file
- * Contains \Plugin\inmail\Fetcher\FetcherInterface.
+ * Contains \Plugin\inmail\Deliverer\DelivererInterface.
  */
 
-namespace Drupal\inmail\Plugin\inmail\Fetcher;
+namespace Drupal\inmail\Plugin\inmail\Deliverer;
 
 use Drupal\Component\Plugin\ConfigurablePluginInterface;
 use Drupal\Component\Plugin\PluginInspectionInterface;
 use Drupal\Core\Plugin\PluginFormInterface;
 
 /**
- * Defines methods for fetchers.
+ * Defines methods for deliverers.
  *
- * @ingroup fetching
+ * @ingroup deliverer
  */
-interface FetcherInterface extends ConfigurablePluginInterface, PluginFormInterface, PluginInspectionInterface {
+interface DelivererInterface extends ConfigurablePluginInterface, PluginFormInterface, PluginInspectionInterface {
 
   /**
-   * Returns the fetcher label.
+   * Returns the deliverer label.
    *
    * @return \Drupal\Core\StringTranslation\TranslationWrapper
-   *   The fetcher label.
+   *   The deliverer label.
    */
   public function getLabel();
 
   /**
-   * Connects to the configured mailbox and fetches new mail.
+   * Connects to the configured mailbox and delivers new mail.
    *
    * @return string[]
-   *   The fetched messages, in complete raw form.
+   *   The delivered messages, in complete raw form.
    */
-  public function fetch();
+  public function deliver();
 
 }
diff --git a/src/Plugin/inmail/Fetcher/ImapFetcher.php b/src/Plugin/inmail/Deliverer/ImapDeliverer.php
similarity index 52%
rename from src/Plugin/inmail/Fetcher/ImapFetcher.php
rename to src/Plugin/inmail/Deliverer/ImapDeliverer.php
index c245e95..5ddb9c9 100644
--- a/src/Plugin/inmail/Fetcher/ImapFetcher.php
+++ b/src/Plugin/inmail/Deliverer/ImapDeliverer.php
@@ -1,39 +1,78 @@
 <?php
 /**
  * @file
- * Contains \Drupal\inmail\Fetch\ImapFetcher.
+ * Contains \Drupal\inmail\Deliverer\ImapDeliverer.
  */
 
-namespace Drupal\inmail\Plugin\inmail\Fetcher;
+namespace Drupal\inmail\Plugin\inmail\Deliverer;
+
 use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Logger\LoggerChannelInterface;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\Core\State\StateInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
  * Fetches messages over IMAP.
  *
- * @ingroup fetching
+ * @ingroup deliverer
  *
- * @Fetcher(
+ * @Deliverer(
  *   id = "imap",
  *   label = @Translation("IMAP")
  * )
  */
-class ImapFetcher extends FetcherBase {
+class ImapDeliverer extends DelivererBase implements ContainerFactoryPluginInterface {
+
+  /**
+   * Injected Inmail logger channel.
+   *
+   * @var \Drupal\Core\Logger\LoggerChannelInterface
+   */
+  protected $loggerChannel;
+
+  /**
+   * Injected site state.
+   *
+   * @var \Drupal\Core\State\StateInterface
+   */
+  protected $state;
 
   /**
    * {@inheritdoc}
    */
-  public function fetch() {
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, LoggerChannelInterface $logger_channel, StateInterface $state) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition);
+    $this->loggerChannel = $logger_channel;
+    $this->state = $state;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+    return new static(
+      $configuration,
+      $plugin_id,
+      $plugin_definition,
+      $container->get('logger.factory')->get('inmail'),
+      $container->get('state')
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function deliver() {
     // Get details from config and connect.
-    // @todo Return silently if not configured.
-    // @todo Return noisily if misconfigured. Possibly stop retrying.
+    // @todo Return noisily if misconfigured or imap missing. Possibly stop retrying.
     $mailbox_flags = $this->configuration['ssl'] ? '/ssl' : '';
     $mailbox = '{' . $this->configuration['host'] . ':' . $this->configuration['port'] . $mailbox_flags . '}';
     $imap_res = imap_open($mailbox, $this->configuration['username'], $this->configuration['password']);
 
     if (!$imap_res) {
-      // @todo Inject logger.
       // @todo Consider throwing an exception.
-      \Drupal::logger('inmail')->error('Fetcher connection failed: @error', ['@error' => implode("\n", imap_errors())]);
+      $this->loggerChannel->error('Deliverer connection failed: @error', ['@error' => implode("\n", imap_errors())]);
       return array();
     }
 
@@ -55,7 +94,7 @@ class ImapFetcher extends FetcherBase {
 
     // Save number of unread messages.
     // @todo Create a Monitoring sensor for this state key.
-    \Drupal::state()->set('inmail.fetcher.imap.remaining', count($unread_ids));
+    $this->state->set('inmail.deliverer.imap.remaining', count($unread_ids));
 
     // Close resource and return messages.
     imap_close($imap_res);
@@ -81,35 +120,64 @@ class ImapFetcher extends FetcherBase {
    * {@inheritdoc}
    */
   public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
-    // @todo Add descriptions here and/or in FetcherBase.
+    $form['info'] = array(
+      '#type' => 'item',
+      '#markup' => $this->t('Please refer to your email provider for the appropriate values for these fields.'),
+    );
+
     $form['host'] = array(
       '#type' => 'textfield',
       '#title' => $this->t('Host'),
       '#default_value' => $this->configuration['host'],
     );
+
     $form['port'] = array(
       '#type' => 'number',
       '#title' => $this->t('Port'),
       '#default_value' => $this->configuration['port'],
+      '#description' => $this->t('The standard port number is 143, or 993 when using SSL.'),
     );
+
     $form['ssl'] = array(
       '#type' => 'checkbox',
       '#title' => $this->t('Use SSL'),
       '#default_value' => $this->configuration['ssl'],
     );
+
     $form['username'] = array(
       '#type' => 'textfield',
       '#title' => $this->t('Username'),
       '#default_value' => $this->configuration['username'],
     );
-    // @todo Password field cannot have #default_value. Hide field unless user checks to change password?
+
+    // Password field cannot have #default_value. To avoid forcing user to
+    // re-enter password with each save, password updating is conditional on
+    // this checkbox.
+    $form['password_update'] = array(
+      '#type' => 'checkbox',
+      '#title' => $this->t('Update password'),
+    );
+
     $form['password'] = array(
       '#type' => 'password',
       '#title' => $this->t('Password'),
+      '#states' => array(
+        'visible' => array(
+          ':input[name=password_update]' => array('checked' => TRUE),
+        ),
+      ),
     );
+
+    // Always show password field if configuration is new.
+    if ($form_state->getFormObject()->getEntity()->isNew()) {
+      $form['password_update']['#access'] = FALSE;
+      $form['password']['#states']['visible'] = array();
+    }
+
     $form['batch_size'] = array(
       '#type' => 'number',
       '#title' => $this->t('Batch size'),
+      '#default_value' => $this->configuration['batch_size'],
       '#description' => $this->t('How many messages to fetch on each invocation.'),
     );
 
@@ -120,14 +188,20 @@ class ImapFetcher extends FetcherBase {
    * {@inheritdoc}
    */
   public function submitConfigurationForm(array &$form, FormStateInterface $form_state) {
-    $this->setConfiguration(array(
+    $configuration = array(
       'host' => $form_state->getValue('host'),
       'port' => $form_state->getValue('port'),
       'ssl' => $form_state->getValue('ssl'),
       'username' => $form_state->getValue('username'),
-      'password' => $form_state->getValue('password'),
       'batch_size' => $form_state->getValue('batch_size'),
-    ));
+    ) + $this->getConfiguration();
+
+    // Only update password if "Update password" is checked.
+    if ($form_state->getValue('password_update')) {
+      $configuration['password'] = $form_state->getValue('password');
+    }
+
+    $this->setConfiguration($configuration);
   }
 
 }
diff --git a/src/Tests/InmailWebTest.php b/src/Tests/InmailWebTest.php
index 8afd11b..931f675 100644
--- a/src/Tests/InmailWebTest.php
+++ b/src/Tests/InmailWebTest.php
@@ -53,6 +53,29 @@ class InmailWebTest extends WebTestBase {
     $this->drupalPostForm(NULL, ['return_path' => ''], 'Save configuration');
     $this->assertText('The configuration options have been saved.');
 
+    // Check Deliverer list.
+    $this->clickLink('Mail deliverers');
+    $this->assertText('There is no Mail deliverer yet.');
+
+    $this->clickLink('Configure new deliverer');
+    $edit = array(
+      'label' => 'Test IMAP Deliverer',
+      'id' => 'test_imap',
+      'plugin' => 'imap',
+    );
+    $this->drupalPostAjaxForm(NULL, $edit, 'plugin');
+    $edit += array(
+      'host' => 'imap.example.com',
+      'username' => 'user',
+      'password' => 'pass',
+    );
+    $this->drupalPostForm(NULL, $edit, 'Save');
+    $this->assertText('Test IMAP Deliverer');
+
+    $this->assertLink('Configure');
+    $this->clickLink('Disable');
+    $this->clickLink('Enable');
+
     // Check Analyzer list.
     $this->clickLink('Message analyzers');
     $this->assertText('Standard DSN Analyzer');
diff --git a/src/Tests/IntegrationTest.php b/src/Tests/IntegrationTest.php
index 7a5bc7e..15b1ef2 100644
--- a/src/Tests/IntegrationTest.php
+++ b/src/Tests/IntegrationTest.php
@@ -64,7 +64,7 @@ class IntegrationTest extends WebTestBase {
     $sent_mails = $this->drupalGetMails();
     $raw = static::generateBounceMessage(array_pop($sent_mails));
     // In reality the message would be passed to the processor through a drush
-    // script or a mail fetcher.
+    // script or a mail deliverer.
     \Drupal::service('inmail.processor')->process($raw);
 
     // Check send state.