Index: core/kernel/utility/email.php
===================================================================
--- core/kernel/utility/email.php
+++ core/kernel/utility/email.php
@@ -229,11 +229,12 @@
 	/**
 	 * Sends e-mail now or puts it in queue
 	 *
-	 * @param int $recipient_user_id
-	 * @return bool
-	 * @access public
+	 * @param integer $recipient_user_id Recipient user id.
+	 * @param boolean $immediate_send    Immediate send.
+	 *
+	 * @return boolean
 	 */
-	public function send($recipient_user_id = null)
+	public function send($recipient_user_id = null, $immediate_send = null)
 	{
 		$this->recipientUserId = $recipient_user_id;
 
@@ -309,9 +310,18 @@
 			$this->sender->setLogData($this->logData);
 		}
 
-		$delivery = isset($this->params['delivery']) ? $this->params['delivery'] : $this->Application->ConfigValue('EmailDelivery');
+		if ( !isset($immediate_send) ) {
+			if ( isset($this->params['delivery']) ) {
+				$delivery = $this->params['delivery'];
+			}
+			else {
+				$delivery = $this->Application->ConfigValue('EmailDelivery');
+			}
+
+			$immediate_send = $delivery == EmailDelivery::IMMEDIATE;
+		}
 
-		return $this->sender->Deliver(null, $delivery == EmailDelivery::IMMEDIATE);
+		return $this->sender->Deliver(null, $immediate_send);
 	}
 
 	/**
Index: core/units/email_templates/email_template_eh.php
===================================================================
--- core/units/email_templates/email_template_eh.php
+++ core/units/email_templates/email_template_eh.php
@@ -30,6 +30,7 @@
 			$permissions = Array (
 				'OnFrontOnly' => Array ('self' => 'edit'),
 				'OnSaveSelected' => Array ('self' => 'view'),
+				'OnProcessEmailQueue' => Array ('self' => 'add|edit'),
 				'OnExportEmailTemplates' => Array ('self' => 'view'),
 
 				'OnSuggestAddressJSON' => Array ('self' => 'add|edit'),
@@ -217,6 +218,22 @@
 		}
 
 		/**
+		 * [AJAX] Process emails from queue.
+		 *
+		 * @param kEvent $event Event.
+		 *
+		 * @return     void
+		 * @deprecated 5.3.0-B1
+		 * @see        EmailQueueEventHandler::OnProcessAjax()
+		 */
+		function OnProcessEmailQueue($event)
+		{
+			kUtil::deprecatedMethod(__METHOD__, '5.3.0-B1', 'EmailQueueEventHandler::OnProcessAjax');
+
+			$event->CallSubEvent('email-queue:OnProcessAjax');
+		}
+
+		/**
 		 * Prefills module dropdown
 		 *
 		 * @param kEvent $event
Index: core/units/helpers/mailing_list_helper.php
===================================================================
--- core/units/helpers/mailing_list_helper.php
+++ core/units/helpers/mailing_list_helper.php
@@ -270,14 +270,22 @@
 		/**
 		 * Sent given messages from email queue.
 		 *
+		 * @param array|null $messages Messages.
+		 *
 		 * @return integer
 		 */
-		function processQueue()
+		function processQueue(&$messages = null)
 		{
 			/** @var kEmailSendingHelper $esender */
 			$esender = $this->Application->recallObject('EmailSender');
 
-			$messages = $this->getMessages();
+			if ( !isset($messages) ) {
+				$messages = $this->getMessages();
+			}
+			else {
+				kUtil::deprecatedArgument(__METHOD__, '5.3.0-B1', 'The "$messages" parameter is deprecated.');
+			}
+
 			$message_count = count($messages);
 
 			if ( !$message_count ) {
@@ -383,4 +391,4 @@
 
 			return $value;
 		}
-	}
\ No newline at end of file
+	}
Index: core/units/mailing_lists/mailing_list_eh.php
===================================================================
--- core/units/mailing_lists/mailing_list_eh.php
+++ core/units/mailing_lists/mailing_list_eh.php
@@ -30,6 +30,7 @@
 			$permissions = Array (
 				'OnCancelMailing' => Array ('self' => 'edit'),
 				'OnGenerateEmailQueue' => Array ('self' => true),
+				'OnProcessEmailQueue' => Array ('self' => true),
 				'OnGetHtmlBody' => Array ('self' => 'edit'),
 			);
 
@@ -254,6 +255,25 @@
 		}
 
 		/**
+		 * Allows to safely get mailing configuration variables
+		 *
+		 * @param string $variable_name Variable name.
+		 *
+		 * @return     integer
+		 * @deprecated 5.3.0-B1
+		 * @see        MailingListHelper::getSetting()
+		 */
+		function _ensureDefault($variable_name)
+		{
+			kUtil::deprecatedMethod(__METHOD__, '5.3.0-B1', 'MailingListHelper::getSetting');
+
+			/** @var MailingListHelper $mailing_list_helper */
+			$mailing_list_helper = $this->Application->recallObject('MailingListHelper');
+
+			return $mailing_list_helper->getSetting($variable_name);
+		}
+
+		/**
 		 * Generates email queue for active mailing lists
 		 *
 		 * @param kEvent $event
@@ -333,6 +353,22 @@
 		}
 
 		/**
+		 * [SCHEDULED TASK] Process email queue from cron
+		 *
+		 * @param kEvent $event Event.
+		 *
+		 * @return     void
+		 * @deprecated 5.3.0-B1
+		 * @see        EmailQueueEventHandler::OnProcess()
+		 */
+		function OnProcessEmailQueue($event)
+		{
+			kUtil::deprecatedMethod(__METHOD__, '5.3.0-B1', 'EmailQueueEventHandler::OnProcess');
+
+			$event->CallSubEvent('email-queue:OnProcess');
+		}
+
+		/**
 		 * Returns HTML of sent e-mail for iframe
 		 *
 		 * @param kEvent $event