Is there a setting or configuration change that will turn off the
suppression of duplicate messages by the MercuryD module in Mercury32?

This function is preventing many users in our organization from
receiving email notification of postings to a particular Yahoo group to
which they are all subscribed.

The "Received:" header properly contains the unique email address of
each user, but when the messages are retrieved together in one polling
cycle they are deemed duplicates by MercuryD and all but the first
user's message is discarded.

Thanks in advance for any help you can give me or any solutions you can
point me to.