Insights from the stack

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

Email Deliverability

The agency email security audit: a repeatable £500 offer

This is a productised service that any web or digital agency can start selling this week. It generates £500-1,500 per engagement, takes about 3-4 hours of actual work, and has an extremely high conversion rate from the first conversation because the value is obvious and the price is low. It also leads directly into a £50-150/month recurring monitoring service, which is where the real margin is.

5 min read · 2 Apr 2026
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