Microsoft Exchange Server is the server side of a client–server, collaborative application product developed by Microsoft.
No doubt it is one of the most used Microsoft’s product which will take care of emails, contacts, calendaring, and tasks. You can store data and there is mobile as well as a web-based support, using which you can access information.
[ Official website download link ]
It can be quite a costly product to own depending on the budget of your company. For those of you, who are looking for an alternative, there is good news:
Alternative Software for Microsoft Exchange Server: