refs https://github.com/TryGhost/Team/issues/2367
This ensures that a Member is not considered subscribed to any emails, so that
counts for newsletter recipients are correct. Eventually we will filter members
on their email suppression status but this is not implemented yet.
refs https://github.com/TryGhost/Team/issues/2267
This package contains definitions for the public interface of the
email suppression list as well as an abstract implementation.
