From 199fce8038086dca874029114690bd0ec68aab37 Mon Sep 17 00:00:00 2001
From: slater0013 <49311455+slater0013@users.noreply.github.com>
Date: Fri, 28 May 2021 11:08:05 +0200
Subject: [PATCH] Auto-Submitted mail header added

Auto-Submitted header should be added to every mail sent by an automatic system, such as CRON jobs, etc. Auto-Reply systems should NOT reply when this header is set to 'auto-generated'.
---
 lib/private/Mail/Mailer.php | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/private/Mail/Mailer.php b/lib/private/Mail/Mailer.php
index e31784db58..4862826e40 100644
--- a/lib/private/Mail/Mailer.php
+++ b/lib/private/Mail/Mailer.php
@@ -188,6 +188,10 @@ class Mailer implements IMailer {
 		if (empty($message->getFrom())) {
 			$message->setFrom([\OCP\Util::getDefaultEmailAddress('no-reply') => $this->defaults->getName()]);
 		}
+		
+		// Add Auto-Submitted mail header. 'auto-generated' value should be set when email is sent by a script such as CRON jobs, etc.
+		$headers = $message->getSwiftMessage()->getHeaders();
+		$headers->addTextHeader('Auto-Submitted', 'auto-generated');
 
 		$failedRecipients = [];