Anything that helps us handle our never-ending email load is welcome in our productivity toolbox. And just in time for holiday away messages and event invites, Google's latest addition to its Inbox app is just the thing we've been looking for.Now, instead of solely having a "Reply" button, Inbox will surface three smart replies you can tap; the app will then automatically start an email with that response. So if your colleague asks a question like "Have you planned when your vacation will be?" it'll give you options such as "No plans yet," "I just sent them to you," and "I'm working on them." You can reply back with just that simple message, or add more detail yourself.The update is impressive if a little creepy. In order to surface relevant responses, Google obviously needs to read and understand the content of your email. However, the company insists no humans are peeping at your conversations."In developing Smart Reply, we adhered to the same rigorous user privacy standards we’ve always held — in other words, no humans reading your email," senior research scientist Greg Corrado explained in a blog post . "This means researchers have to get machine learning to work on a data set that they themselves cannot read, which is a little like trying to solve a puzzle while blindfolded — but a challenge makes it more interesting."Google explains how the process works on its research blog (and it's seriously impressive, if you want to give it a read). Basically, the whole system is machine-learning based. Google analyzes and simplifies what's said in an email — breaking down a maybe 100-plus word email into its simplest form, "Are you free tomorrow?", for example — then crafts a response word by word. When the system is surfacing responses, it checks the language of each to make sure it's not doubling up, offering multiple versions of the same reply. Both networks learn and become trained, rather than being pre-programmed with auto-responses, so they will improve over time as you, and others, use the tool.We're eager to start using this new smart replying capability, because 10 seconds not spent writing an email is...well, 10 seconds we can spend doing just about anything else.