# Mac Mail Threading

**URL:** <https://meta.discourse.org/t/mac-mail-threading/56194>\
**Category:** Product Support\
**Created:** [January 23, 2017, 7:57am UTC](https://meta.discourse.org/t/mac-mail-threading/56194 "2017-01-23T07:57:08Z")\
**Posts on this page:** 1\
**Showing post:** 1

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**Author:** ![peternlewis](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/peternlewis/32/108888_2.png) [@peternlewis](https://meta.discourse.org/u/peternlewis)\
**Post date:** [January 23, 2017, 7:57am UTC](https://meta.discourse.org/t/mac-mail-threading/56194/1 "2017-01-23T07:57:08Z")

</div>

Yes, sigh, I know, again.

1.7 breaks the workaround we had for Mac Mail threading, namely always including “Re:” at the start of the subject

Setting for email subject `Re: [%{site_name}] %{optional_pm}%{topic_title}`

Unfortunately, Discourse 1.7 sensibly does not include an “In-Reply-To” on the first post, and this results in the first post being threaded separately from the replies in Mac Mail.

I have a hack to put the “In-Reply-To” back:

```diff
         @message.header['Message-ID'] = incoming_message_id || post_message_id
- if post && post.post_number > 1
+ if post
           @message.header['In-Reply-To'] = referenced_post_message_ids.first || topic_message_id
+ end
+ if post && post.post_number > 1
           @message.header['References'] = [topic_message_id, referenced_post_message_ids].flatten.compact.uniq
         end

```

but this is obviously less than ideal. That said, I’ve got no ideas for any better solution, and the alternative (the initial post being threaded separately from replies) is very bad for those of us using Mailing List Mode since it appears as an unanswered question even though there are answers.

I’m hopeful someone else will have some better idea to restore Mac Mail threading, or a better workaround, or something…? Failing that, at least this documents the issue for anyone else with lots of Mac forum users.

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