On 8/31/2017 11:45 AM, Tom Browder wrote: > > I've seen the docs about the prepend method, but I wonder about how > to find out if a desired header is already used--would that cause a > problem? Also, I guess I only would need the headers for outgoing > mail from the mailing lists, but I think that is covered in the docs. >
Surely your maillist software adds these headers. If it doesn't, get better maillist software. There should be no need to add maillist headers in postfix. You're making this too hard. To answer your question, PREPEND has no way to add a header if it doesn't exist. Technically, multiple X- or LIST- headers aren't a problem, but no telling how some random site's spam engine will rank it. But don't use postfix for adding maillist headers. Use your maillist software. -- Noel Jones
