>Yes. It's been months and we need to know ASAP ... ASAP? Nothing has changed for months. Google has repeatedly said that they're not going to turn on DMARC until ARC is available. R's, John PS: For my lists, I have a shim that rewrites addresses like marissa@xxxxxxxxx to marissa@xxxxxxxxxxxxxxxxxxxx, and sets up temporary forwards. It's simple and works nicely, and since it's a shim between the list manager and the MTA, it doesn't require surgery on mailman.