Set explicit Message-ID in ExceptionMailerCronjob

diff --git a/wcfsetup/install/files/lib/system/cronjob/ExceptionMailerCronjob.class.php b/wcfsetup/install/files/lib/system/cronjob/ExceptionMailerCronjob.class.php
index 2886a8b15dd5e9e4ba1b8bba34828a43cb1583bd..eb1d9591d845ae6267a1943e51edac972bc83c11 100644 (file)
--- a/wcfsetup/install/files/lib/system/cronjob/ExceptionMailerCronjob.class.php
+++ b/wcfsetup/install/files/lib/system/cronjob/ExceptionMailerCronjob.class.php
@@ -89,6 +89,11 @@ class ExceptionMailerCronjob extends AbstractCronjob
         $language = LanguageFactory::getInstance()->getDefaultLanguage();
 
         $email = new Email();
+        $email->setMessageID(\sprintf(
+            'com.woltlab.wcf.exceptionMailer/%d/%s',
+            $timestamp,
+            \bin2hex(\random_bytes(8))
+        ));
         $email->addRecipient(new Mailbox(MAIL_ADMIN_ADDRESS, null, $language));
         $email->setSubject($language->getDynamicVariable('wcf.acp.exceptionLog.email.subject', [
             'date' => $timestamp,