Mail’s Email Aliases, and Complexity Hidden
It’s a simple and elegant solution, but not at all discoverable; I needed documentation to help me find the setting, which is unusual and troubling for a UI nerd. I might’ve been understanding if they’d just nixed the feature, as Mail is bundled with OS X and one could argue that it’s not supposed to be for Power Users. But Apple’s designers and engineers took a different route. They added the feature and obviously put a lot of work into it, considering new aliases show up in the menu automagically, but they opted for zero interface. No fifteen pixels of fame.