My Open Journal Systems installation stopped sending any messages right after the last core update. Outgoing notifications, reviewer invitations—nothing is leaving the server. I have already double-checked the SMTP credentials and other mail server settings, so the problem sits somewhere deeper in OJS or its post-update configuration. I need a quick but solid fix that gets every automated email flowing again without landing in limbo or error queues. You’ll likely want to dig through the OJS logs, confirm the upgrade didn’t overwrite config.inc.php values, and verify that the mail transport (PHPMailer, sendmail or SMTP) is wired correctly. Deliverable (acceptance criteria) • All standard OJS emails send successfully from the UI and reach at least one external test inbox. • No fatal errors or mail-related warnings appear in the OJS or web-server error logs. • A short note outlining what was wrong and what you changed so the issue doesn’t resurface on the next update. If you’re comfortable troubleshooting post-upgrade quirks in OJS, this should be straightforward. I’m ready to provide admin access and test accounts the moment we agree to proceed.