Automatically replying to emails in Gmail is a task that actually can’t be accomplished natively , but it can be done by pairing a few of our favorite tools. Gmail Filters and the Canned Responses Lab are very useful on their own, but they can actually be used in tandem to automatically reply to incoming messages.
If you’re not familiar with the Canned Responses Lab, it allows you to create templates of emails that you send often, and quickly insert the entire template into an email. Meanwhile, Gmail filters can automatically take action upon an email based on a pre-set criteria. For example, you could set a Gmail filter to always mark internal emails as important.
One of the actions a Gmail filter can take is automatically assign a Canned Response template to an incoming message and send a reply. This is an extremely useful tool if you find yourself sending the same message over and over again. Even if the messages arrive infrequently, pairing Gmail filters with Canned Responses can make those emails on less thing to worry about.