On Thu, Jun 25, 2020 at 2:27 PM jim stephens via cctalk < cctalk@classiccmp.org> wrote:
> The current message > "From" field contains the name of the original sender but with the > encoded address of the list as the email address > Unfortunately now there's no practical way for a mailing list to avoid rewriting the From header to indicate that the messages are sent from the list. If you don't do that, many (or most) mail servers (MTAs) will silently drop the mail due to DKIM/SPF/DMARC failures. If I send mail from f...@example.com to a classiccmp.org list, and then the list sends it to all the subscribers _without_ rewriting the From header, many (or most) receiving MTAs will find that the message fails origin verification because classiccmp.org can't be validated as a legitimate SMTP originator for email from example.com. I'm surprised that use of an "X-Original-From" header or similar isn't commonly used to work around this. Possibly people may think that it would help spammers harvest email addresses, but it wouldn't make the harvesting problem any worse than it was before From rewriting. Some list software puts the entire original From address in the comment part of the rewritten From header, rather than only the comment part of the original.
