ContactMonkey uses EWS in order to expand Distribution lists, dynamic lists and Office 365 groups in order to count the total number of users in the list that has been provided to us. We use this recipient count as part of the analytics for your Internal Comms personnel to help track their engagement. However, using EWS through the Office 365 web add-in has several restrictions, one of which is that the API has a 1mb limit on the response.
A ContactMonkey utility account provides the login credentials and access for the ContactMonkey Server to talk to Exchange EWS to expand dynamic distribution lists.
The service account can be set-up either with Exchange Management console or using Active Directory Users and Computers controls.
No admin permissions are required for this mailbox, this service account mailbox is a user (K1 level in Office365) level mailbox (email address and password), which is only utilized by the ContactMonkey Server for authentication with EWS when expanding membership of distribution groups. The mailbox name is not important and will not be used for any send from address, most customers use firstname.lastname@example.org.
The service account credentials are input into the ContactMoney Server Manager > Exchange Web Services control page, and will be stored encrypted with AES-256.
If you will be sending to membership protected lists (groups with membership hidden), then the service account must be added to the security group with permissions to view membership in order to expand the list.