Download : Microsoft Exchange Server 2019 Public preview

July 24, 2018 we announced the preview build of Exchange Server 2019 and you can download it from here 

So you can download, test it, take a look at the Preview and make use of it. For detailed info please refer our EHLO blog post: https://blogs.technet.microsoft.com/exchange/2018/07/24/exchange-server-2019-public-preview/

Hope this helps.