When building PowerShell scripts that leverage the EWS Managed API, we can use impersonation to access a user's mailbox on their behalf without having to provide their credentials. In order to utilize impersonation, we need permissions inside the Exchange organization, and then we need to configure the ExchangeService connection object with the impersonated user ID. In this recipe, you'll learn how to assign the permissions and write a script that uses EWS impersonation.
You will need to use the Exchange Management Shell in this recipe in order to assign permissions for Application Impersonation.
The first thing you need to do is assign your account the ApplicationImpersonation RBAC role from the Exchange Management Shell:
New-ManagementRoleAssignment -Role ApplicationImpersonation ` -User administrator
After we've been granted the permissions, we need to import the EWS Managed API assembly and configure the ExchangeService connection object...