Find Your Messages
OS X’s Spotlight search feature automatically indexes all your Mail messages for super-fast searching, and you can search for them either within Mail or using the system-wide Spotlight menu.
El Capitan adds the capability to search using natural language rather than relying on special keywords or formulations. However, if you want to do complex searches, you can—all the search capabilities from Yosemite are still there too. With a flexible system of search tokens (which I explain in a moment), Boolean searches, and other options, you can find almost any message you can describe.
And, you can even save a search by converting it into a smart mailbox, as I describe at the end of this chapter, in Work Smarter with Smart Mailboxes ...