朱超 writes:

hi, how to deal with arc with using mailman+exim4? Thanks for your suggestion.

The preferred way to use such protocols is to deal with it entirely at the MTA level. I recommend asking about it on the Exim channels.

If for some reason that is not possible, you can do it in Mailman, but this has a number of disadvantages, including inability to authenticate the peer using SPF. See https://docs.mailman3.org/projects/mailman/en/latest/src/mailman/handlers/do... for basic information about using ARC in Mailman, and see the file schema.cfg for the settings used in configuring it (they probably won't be in your mailman.cfg yet because the recommended approach is to do DKIM, ARC, SPF, and optionally DMARC in the MTA).