Add SPF and/or DKIM and/or others for lists.torproject.org

It occurred to me yesterday that while we will have a tough time promising the internet that all @torproject.org emails will come from eugeni, it is easy to promise that all the @lists.torproject.org emails will come from eugeni -- because I think that's already the case and we have no plans to change it.

I believe @lavamind already (yesterday) enabled an spf line for the lists.tpo domain. How's that going?

We could go farther and enable dkim or dmarc or whatever else we pick as well (assuming they can each be applied to subdomains of a domain that itself does not yet have them enforced).