from_is_list
- This applies to all non-digest messages sent by the list. For settings that apply only to messages whose From: domain publishes a DMARC p=reject or p=quarantine policy, see the dmarc_moderation_action description in the Sender filters section.
If set to Munge From, it replaces the From: header address with the list’s posting address to mitigate issues stemming from the original From: domain’s DMARC or similar policies and puts the original From: address in a Reply-To: header.
If set to Wrap Message it wraps the original message as a MIME subpart of an outer message with From: and Reply-To: headers as above.
I don’t think Discourse provides a similar feature. I’ve not seen any site settings that would be a match. And I browsed all email related settings a few times in the past few days, in the context of an ongoing mailman2 migration.