When adding one recipient to an exchange distribution list, exchange removes+adds all members

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Senior Member

When adding or removing one recipient to an exchange distribution list, exchange removes all the members then adds all of them back in.  This creates unnecessary replication traffic between active directory domain controllers, as all the user objects are changed, and creates unnecessary security event log entries, N*2+1 instead of just 1 (where N is the original number of members in the group).  This increased volume of events actually make the change opaque, because N users are removed and N+1 or N-1 are then added, so finding who the +/-1 user is difficult or impossible.

Tested in Exchange 2016-CU17

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