Exchange server

I’m new at this and need some help. The company that I work for has but a domain from network solution and has a website and email accounts with goddady.com We own an exchange server in the company that is not being used and the idea is to connect it to the pop email accounts that everybody is using, and also create more new internal email accounts.

I’m having problems configuring the DNS, the mx records to point to the services. Can anyone help?