It looks like Houdah is using a plugin within Mail to provide search results. Apple doesn't actually provide a public API for this, and they don't officially support Mail plugins.   Using unsupported or private APIs means that any changes made by Apple can kill the feature at any time; Hacks often quickly prove themselves to be unreliable as Apple make regular changes to macOS.   I don't want to detract from Houdah's choice to add it, but there are no features in Alfred relyi