Well, sharing the folders is one possible solution, but have you looked at the alternate options?
Namely, create a "distribution list" email address that automatically forwards to the desired accounts.
- Prevents users from accidentally deleting messages for all users
- Everyone gets a copy, right in their inbox
- User education required. If one user replies to an email without doing a Reply-All and including the group email address, the other people on the group will be unaware that it was replied to.
Release 8.0.7.GA.6021.UBUNTU12.64 FOSS Edition