How do I include a particular person in our global address book that is nothing but a placeholder for their external email address?
For example, I want John Doe to show up as someone we can pick from our global address list as well as being able to include inside distribution lists...but their mailbox is hosted elsewhere...such as JohnDoe@gmail.com.
In MS Exchange, we have external contacts where the email address is SMTP:JohnDoe@gmail.com and they look a bit different so we can tell this is an external address...but their email is not stored here...it is just a placeholder to allow us to find and communicate to them.
EDIT: Solution - Add a distribution list for each external contact.
firstname.lastname@example.org (contains email@example.com) (can receive email enabled)
firstname.lastname@example.org (contains email@example.com) (can receive email enabled)
firstname.lastname@example.org (contains email@example.com) (can receive email enabled)