Hi, I've been studying SPF, DKIM, DMARC and a bit of ARC. And I've been wondering if a list [including this one] could be more friendly by using Reply-To: to hold the message sender.
These spam-fighting methods have the greatest difficulty with email forwarding and lists because: - changes to message headers usually invalidate a DKIM message - bypass routes usually invalidate SPF settings - DMARC requires either to hold _and_ the domain to match the From: header An indirect MTA cannot produce a DKIM message on the originator's domain, and DMARC demands that to align with the From: header. An indirect MTA may alter envelope from to make SPF work, but DMARC additionally requires the envelope sender to align with the From: header. A way to send email in line with DMARC might be: 1. stash the original sender in the Reply-To: header 2. use a From: header with a list address under the list bounce domain 3. setup SPF in the list bounce domain 4. this should pass on DMARC, because SPF passes and DKIM fails I'd like to learn if this approach is considered sound by the list. Cheers, Rick van Rein
