Re: Where is the source code of the mailing list archive's web interface?

[Tim Lee]

> I'm sorry, I'm very busy currently, but I believe I've answered that
> question on this list in the last year and said that a patch is welcome,
> please check the archive.

Okay, I've found the thread:
"Source code for "reply via email" on lists.gnu.org"
(https://lists.gnu.org/archive/html/mailman/2020-05/msg00003.html)

Patch:

diff --git a/mp/yyz.py b/mp/yyz.py
index a403aa9..41891b0 100644
--- a/mp/yyz.py
+++ b/mp/yyz.py
@@ -40,7 +40,7 @@ def handler (req):
     if form.has_key ('a') and form.has_key ('b') and \
        form.has_key ('c') and form.has_key ('d'):
         req.headers_out.add ('Location',
-                            'mailto:%s@%s?In-Reply-To=%s&Subject=%s' \
+                            'mailto:%s@%s?In-Reply-To=<%s>&Subject=%s' \
                              % (quote(form['a']), quote(form['c']),
                                 quote(form['d']), quote(form['b'])))