Google on Wednesday began allowing users to extend online searches to include messages stored in accounts at Web-based email service Gmail.

“Sometimes the best answer to your question isn’t available on the public Web — it may be contained elsewhere, such as in your email,” Google search senior vice president Amit Singhal said in a blog post.

“We think you shouldn’t have to be your own mini search engine to find the most useful information; it should just work.”

Google invited people to visit google.com/experimental/gmailfieldtrial to sign up to take part in the new feature, which was still taking shape.

“We’re developing a way to find this information for you that’s useful and unobtrusive, and we’d love your feedback,” Singhal said.