This is an experience (rant) I share for the sake of those who may have something similar in their lives. As of this writing I am leading a Lotus Notes 8.5 to Exchange 2010 migration. Our requirements drove the usage of a co-existence solution offered by companies such as Binary-Tree or Quest. Co-existence is defined as sharing a single mail namespace between Exchange and Lotus Notes.
In our case Binary-Tree was chosen, however their co-existence solution fell somewhat short when it came to preserving functionality for migrated users in need of the ability to send mail to restricted mail groups in...