diff --git a/includes/class-wc-background-emailer.php b/includes/class-wc-background-emailer.php
index 396f7a4c1ac..c5b9412abe8 100644
--- a/includes/class-wc-background-emailer.php
+++ b/includes/class-wc-background-emailer.php
@@ -37,7 +37,7 @@ class WC_Background_Emailer extends WP_Background_Process {
 		$this->action = 'wc_emailer';
 
 		// Dispatch queue after shutdown.
-		add_action( 'shutdown', array( $this, 'dispatch_queue' ) );
+		add_action( 'shutdown', array( $this, 'dispatch_queue' ), 100 );
 
 		parent::__construct();
 	}
@@ -75,11 +75,40 @@ class WC_Background_Emailer extends WP_Background_Process {
 		return false;
 	}
 
+	/**
+	 * Finishes replying to the client, but keeps the process running for further (async) code execution.
+	 *
+	 * @see https://core.trac.wordpress.org/ticket/41358 .
+	 */
+	protected function close_http_connection() {
+		// Only 1 PHP process can access a session object at a time, close this so the next request isn't kept waiting.
+		// @codingStandardsIgnoreStart
+		if ( session_id() ) {
+			session_write_close();
+		}
+		// @codingStandardsIgnoreEnd
+
+		wc_set_time_limit( 0 );
+
+		// fastcgi_finish_request is the cleanest way to send the response and keep the script running, but not every server has it.
+		if ( is_callable( 'fastcgi_finish_request' ) ) {
+			fastcgi_finish_request();
+		} else {
+			// Fallback: send headers and flush buffers.
+			if ( ! headers_sent() ) {
+				header( 'Connection: close' );
+			}
+			@ob_end_flush();
+			flush();
+		}
+	}
+
 	/**
 	 * Save and run queue.
 	 */
 	public function dispatch_queue() {
 		if ( ! empty( $this->data ) ) {
+			$this->close_http_connection();
 			$this->save()->dispatch();
 		}
 	}