Re: Patch series sent via b4 relay have a duplicate/shadow tree?

On Wed, May 06, 2026 at 08:53:07AM -0700, Ackerley Tng wrote:
> Hi,
> 
> I used the b4 email relay for the first time recently and noticed that
> the email tree on lore [1] has a duplicate/shadow tree.
> 
> In the "Thread overview" section, other than the tree with emails
> suffixed with "via B4 relay", there's also the second tree, which
> appears like I replied to each of my emails on the patch series.
> 
> There's a line that says "WARNING: multiple messages have this
> Message-ID", and the diff is [2] just the From email and the message id.
> 
> Is this intended?

This is a side-effect of from-header rewriting. We write all messages we get
via the relay directly to a "b4-sent" feed:

lore.kernel.org/b4-sent/

However, we must rewrite the From: header to actually send the messages out,
because otherwise they will not pass DMARC checks. For this reason, there are
usually 2 slightly different copies of the message on lore.

It's completely benign and the tools will do the right thing.

-K