Can OSX mail auto-search & complete a mail address? In Outlook there is this highly useful feature to automatically search and complete a mail address in the recipient field (To:) with CTRL+K. Even if you never mailed with someone before, it will search for your input in any global address books you're syncing with (like your company's account). When there is only one match, it auto-prefills it, so it saves the hassle of looking someone up, copying their address and only after that pasting it in your mail window

Can OSX mail automatically search and complete a mail address you've never mailed with before, but which is in one of the address books you're syncing with?
Yes, Mail App could auto-fill the email address according to your Contacts even though you've mailed with before. Certainly, you can search the whole Contacts by your self.