How to tell if I have an Exchange account in Outlook 2016
Outlook supports multiple account types such as Microsoft Exchange Server, POP3, IMAP, and Outlook.com (formerly Hotmail). Some features in Outlook require an Exchange account, which is provided by your organization, Office 365, and some Internet hosting providers.
To check your account type in Outlook:
In the main Outlook window, choose File > Account Settings > Account Settings.
On the Email tab, you'll see your accounts and the Type for each.
An Exchange account is listed as Microsoft Exchange.