Recipient Counting for Larger Lists

Want to set up a back-end count for your lists over 20-25,000?

Contact your account manager, and they can begin the process for you.

ContactMonkey uses EWS to expand Distribution lists, dynamic lists, and Office 365 groups 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, including that the API has a 5 MB limit on the response.

To bypass the limitation

In order to bypass this limitation, your team would need to provide us with a utility account that has access to the EWS API and, specifically, this ExpandDL call.  This utility account will only be used to call the ExpandDL call so that we can count the total number of recipients inside the list (and any nested lists). 


If you would like to learn more about how to set up a utility account with ContactMonkey, see below:

  • 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 with the Exchange Management Console or 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 unimportant and will not be used for any send-from address, and most customers use
  • The service account credentials are used on the CM server 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 permission to view membership in order to expand the list.
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