Insights from the stack

Hosting guides, infrastructure deep-dives, and email deliverability from the team that's been running servers since 1992.

Infrastructure

How we configure HAProxy for mail server failover

A single SMTP server is a single point of failure. This is the actual HAProxy configuration we use for mail relay failover, including health checks, stick tables, and SMTP protocol handling.

12 min read · 29 Jan 2026