On Fri, 10 Oct 2014 12:46:50 +0100 Martin Gregorie <mar...@gregorie.org> wrote:
> I've recently noticed what may be a new spamming technique: sending > mail to Yahoo Groups with an invalid group name - since Yahoo! > doesnt! seem! to! use! SPF, this intentional backscatter gets > delivered to the forged recipient address with the payload in the > returned message text. This is actually quite old. The only differences are what you describe later. Another old trick is to send to moderated groups as non-members and have the group moderators reject the messages. Yahoo hasn't yet figured out how to not bounce such messages, it seems.
