Presently I use MailMan for several email lists on my shared hosting servers. Also, I manage a list of 300 and a list of 3500 for friends on a Lyris announce-only server.
If I wanted to have access to my own mailing list server, such as a Lyris or equivalent server, what sort of hosting company would I need? Would a VPS be an option? None of me present hosts likes email servers for obvious reasons. I assume that there are companies that specialize in hosting email servers.
ConstantContact, Google, and Yahoo are not options. All of the lists are full opt-in lists with no spam issues. Most of them are lists I manage for fun as a hobby.
The problem with buying a machine, installing software, and using that is the bandwidth. The traffic on the discussion lists is very sporadic. There could be 1 message with 9 replies (for a total of 10 messages to 100 users) in an hour, after which there may not be a post for a week.