The "recall" feature in Gmail is actually called Undo Send. After you hit send, a small black box appears in the bottom-left corner (on desktop) or bottom-right (on mobile) with an "Undo" link. If you didn't click that immediately, the email is gone. Unlike Outlook, Gmail doesn't actually "pull back" an email from someone's inbox; it just delays sending it for a few seconds to give you a chance to stop it.