[Mailman-Users] Puzzle Regarding Sender Header

[David Eisner]

On Fri, Jan 15, 2010 at 10:23 PM, Mark Sapiro <mark at msapiro.net> wrote:
> Your MTA is rewriting the domain in the Sender: header. The FAQ at
> <http://wiki.list.org/x/uYA9> might be relevant.

This puts me on the right track: Sendmail is definitely rewriting the
headers.  I verified this by sending a message from the server (no
mailman involved), and it rewrite the header.  The FAQ isn't entirely
relevant, as no CNAME is involved (lists.foo.org is a full-fledged A
record), but it's clearly a sendmail config issue.  Thanks for your
help.

-David