The initial setup no longer works with Firefox
Author: mjharwoodCreated May 20, 2021Updated Sep 2, 2026
The guide (https://mailinabox.email/guide.html) says: Open the URL in Firefox. Firefox will say This Connection is Untrusted. Click on I Understand the Risks. Click on Add Exception.
This no longer happens (as of FF 88.0, and probably earlier) The page firefox actually brings up says:
Firefox detected a potential security threat and did not continue to box.liminalflux.com because this website
requires a secure connection.
box.example.com has a security policy called HTTP Strict Transport Security (HSTS), which means that Firefox
can only connect to it securely. You can’t add an exception to visit this site.adding an exception still works in Chrome.
Source: mail-in-a-box/mailinabox