This is a good strategy to follow even if you're a coder among coders. Bosses get really busy sometimes, and may not notice the significance of small achievements. Having a note show up in email, where it can be read later, is a good way to make sure that the benefits of your labors don't go unnoticed. And having a paper trail is good at review time, when bossses go through the exercise of collecting data for their side of the review. If your boss is well-organized, they'll keep separate email folders to collect review material, such as notes from co-workers.