My company has a huge Mailman archive and a majority of the early users still prefer the Mailman interaction workflow.
Management wants Mailman to still run but at the same time to start a phase-based online engagement experience using Discourse (assuming contents have already been migrated from Mailman to kickstart the Discourse community in the preceding phase) while preserving the use of the same mailing list/addresses.
My question is to what extent is that possible and practical using a self-hosting option or Discourse Enterprise plan?
My apologies for not being sure if this topic fits this category
If you choose to migrate to our business or enterprise hosting, we include three days of migration work which is usually enough. See https://www.discourse.org/migrations for details on migrating to Discourse.
Yes, you can create a read-only mirror of the mailing list. All emails that get sent to the mailing list will appear inside a category in Discourse. Please note, we recommend that you disallow any replies in such a category to prevent any confusion, because Discourse will never send emails to the mailing list.