You will need a Exchange account with ApplicationImpersonations permissions to connect to your Exchange server. Step 1 till 9 of the following guide will show you how to add ApplicationImpersonations permissions to an existing account
1. Go to Exchange Admin Center on your Exchange server (https://<server name>/ecp) and log in using an Exchange admin account.
2. Click permissions
3. Click on New
4. Provide a name(4a) and click New(4b)
5. Find ApplicationImpersonation in the list and double-click it(5a) and click OK(5b)
6. Click New under Members
7. Find the account to which you will assign ApplicationImpersonation permissions and double-click it(7a) and click OK(7b)
8. Click Save
9. Go to Data Discovery by Cookie Information and login
10. Then go to the Integration page and click Connect on the Exchange Server
11. Fill out the following information regarding your Exchange server and Click(11d).
Username and Password(11a): The credentials of the service account assigned ApplicationImpersonation permissions earlier.
Url(11b): Provide the EWS url for your Exchange server(11b) (https://<server name>/EWS/Exchange.asmx).
Use AQS keyword search(11c): We recommend that you let AQS be active unless your Exchange server does not support it.