In the Mail app on your Mac, in the toolbar, start typing a phrase in the search field (if it’s not shown, click the Search button in the toolbar), then choose a Mail suggestion. Mail

If you had a working @mac.com email address as of July 9, 2008, kept your MobileMe account active, and moved to iCloud before August 1, 2012, you can use @icloud.com, @me.com, and @mac.com email addresses