Do I need to register my mail client app in the Microsoft Partner Center?

I'm trying to create a lightweight mail client to serve a specific need.

I want my users to be able to manage their Outlook emails and calendar in this mail client.

Here are my questions:

• Do I need to register my mail client app via the Microsoft Partner Center?
• What would be the benefit of doing so?
• And if I should do it, what is the process for registering and getting it approved? In other words, how do I register?