On 05.07.18 13:39, David Woodfall wrote: > I've noticed now that my replies in that thread don't have a > In-Reply-To for some reason. When I tag one and attach it with & as > you said it joins fine and adds that. > > Why wouldn't mutt add that? It works fine eg in lists.
It's ticked over 23:00 here, and I'm not recalling anything on the missing In-Reply-To headers, but if there's still poor threading after that's fixed, then here's what my notes say I did, back when: Debug: Maillist posts, lacking In-Reply-To or References headers, and with "Fwd: Re: Fwd: Re:" pollution in the Subject, started multiple threads, and mutt didn't cope: Diagn: :set ? strict_threads strict_threads is unset :set ? sort_re sort_re is set # Default reply_regexp is simplistic, though. Fix: Added in .muttrc: # Note: Keep reply_regexp lower-case, to keep it case-insensitive. # set reply_regexp="^(((re(\\[[0-9]\\])?|aw|fw|fwd|\\?\\?|):)[ \t]*)+" There are even fancier regexes in the list archive, back in 2009/2010, but they have more ambitious agendas. Erik