Why do certain replied emails missing threading when replied back in Mutt?

Question

I use Mutt for emails. I have threads enabled and I can see that most of the emails are threaded in Mutt. So that is all good. But sometimes I reply to an email and the answer(from other person) to my replied email wont be part of any threads. The thing is that when I reply in Mutt (which I use Vim to edit them), the subject parts keeps getting longer and longer with many "Re"s. That is the case with those emails with missing threads.

I have:

set strict_threads="yes"
set sort="threads"
set edit_headers=yes

I am wondering if this has anything to do with Mutt or the person I am communicating over email.

Could this one be the culprit?

set metoo=yes

Any suggestions?

Answer 1

There are 2 methods for grouping messages into threads. The strict method is not by subject, but by analysing the references to previous messages in the message header (in-reply-to and references headers).

I use this method, which is controlled in mutt by setting the option strict_threads.

This works OK in almost every case, and allows the subject to be adjusted without risk of breaking the thread.

Be careful, knowing that you have edit_headers set, not to delete these references as you edit your message.

In the rare cases when someone replies without the correct reference headers, I manually attach it to the thread:

1. tag the child message(s)
2. go to the parent message
3. press & (<link-threads>)

The second method (which is the default, with strict_threads unset) groups messages by subject. This is probably your case, and therefore fails if the subject is modified.

The variable sort_re allows you to specify how picky mutt is about grouping by subject.

Here is online documentation for strict_threads and sort_re.