Quoting Michael Paoli (Michael.Paoli@cal.berkeley.edu):
And yes, did add SPF on list of things to be done/checked: https://www.wiki.balug.org/wiki/doku.php?id=balug:mail_and_lists
o N (future) add appropriate SPF records for @lists.balug.org, @balug.org
One SPF record. One. If you don't believe me, read the spec.