OPNsense Forum

English Forums => 26.1, 26,4 Series => Topic started by: Blackdragon83 on April 22, 2026, 03:40:28 AM

Title: Monit and STARTTLS Issue
Post by: Blackdragon83 on April 22, 2026, 03:40:28 AM
Hello everyone,

I'm trying to set up a reporting system using Monit, with email alerts forwarded through my Hotmail account. However, the setup isn't working, and I'm receiving the following error:

SMTP: Mailserver response error -- 451 5.7.3 STARTTLS is required to send mail [DX0P273CA0003.AREP273.PROD.OUTLOOK.COM 2026-04-21T17:04:23.671Z 08DE9DD04CF197D8]

STARTTLS is mandatory for authentication, but it seems Monit isn't initiating a TLS connection properly. Has anyone successfully configured Monit to send emails via Hotmail/Outlook.com? If so, could you share the correct SMTP settings or any workarounds?