Mail is one of those applications that I continue to use despite changing and testing various mail management applications throughout the Mac App Store. The new options that are being implemented and the customs that I have acquired for a long time, are the main reason why I continue to use the native application for managing my email. It is true that keeps presenting details that they can improve or even implement from other third-party apps, but in principle I'm used to it and there is no other email client that I like more than the many that I have tried to date.
But today I am not going to talk about the email clients that exist and neither what I like in Mail, we are simply going to see how to activate the tabs to obtain greater productivity in email. Apple added in macOS Sierra 10.12 the option to use tabs in addition to its Safari browser and Finder, in the native Calendar, Keynote, Numbers, Pages, Maps and Mail applications. He also announced that this tab system would work in third-party applications, but at the moment nothing new about it.
What we are clear about is that it is very simple to use. To activate it, the first thing we have to do is activate the "Always" function in the System Preferences. This option is found in System Preferences - Dock - Prefer tabs when opening documents - Always. Now when we want to open more tabs in the Mail application we have to press cmd + Alt + N and a new tab will automatically open.