Let's Encrypt Proxy DNS Authentication

Certain use cases preclude DNS dynamic updates to a zone for technical, policy or other reasons. This post explains a simple way to enable automatic DNS-based authorization for Let’s Encrypt certificates – and perhaps for other vendors’ – by way of delegating the authorization challenge to a trusted DNS zone.

Simplified Sendmail Config

This is a quick post documenting the most recent Sendmail setup that I’m testing for a project. It differs slightly from my typical setup on Debian systems, so I’m documenting it here mostly for the sake of keeping notes.