The Architecture of Mailinator is a fascinating read about scaling an SMTP server to 4.5 million emails a day. Which isn't all that interesting except this part:

…the complete set of hardware that mailinator uses is one little server. Just one. A very modest machine with an AMD 2Ghz Athlon processor, 1G of ram (although it really doesn't need that much), and a boring (IDE , low-performance) 80G hard drive. And honestly, its really not very busy at all.

The whole system design is built around being good enough.

The basic tenet is that I do not have to provide perfect service. In order to do that, my hardware requirements would be much higher. Now that would all be fine and dandy if people were paying for the service. I could then provide support and guarantees. But given its free I instead went for, in order, these two design decisions: 1) Design a system that values survival above all else even users (as of course, if its down, users aren't really getting much out of it) 2) Provide 99.99% uptime and accuracy for users.

Thinking about solving problems adaquately, rather than optimally provides a huge amount of freedom to focus on other things. This was a good reminder.