Some of them. In a previous job this was actually the solution my department ended up using - one box running Mailman, with various lists set up for things like special groups, people who need to receive alerts on specialized systems, stuff like that.
The big win was the ability to rapidly subscribe and unsubscribe from lists as you needed them. The actual corporate email distro lists were handled by a dedicated IT team who insisted on tickets for everything, so most people just added filter rules to their inboxes instead of dealing with that mess.
The big win was the ability to rapidly subscribe and unsubscribe from lists as you needed them. The actual corporate email distro lists were handled by a dedicated IT team who insisted on tickets for everything, so most people just added filter rules to their inboxes instead of dealing with that mess.