Do you provide "Mailman only" hosting?
We’re occasionally asked if we can provide Mailman list hosting by itself, without handling the rest of the email for a given domain name.
Unfortunately, this isn’t possible for technical reasons. We’re sorry about that.
It’s also currently not possible for us to provide Mailman hosting for a subdomain — in other words, we can’t provide Mailman list service for “lists.example.com” unless we handle all the mail for example.com.
(Some people who want this service simply sign up for a different domain name for their lists, such as “example-lists.com”.)