# Emails are not threaded in Outlook 2013

**URL:** https://meta.discourse.org/t/emails-are-not-threaded-in-outlook-2013/16501
**Category:** Bug
**Created:** [June 13, 2014, 4:36am UTC](https://meta.discourse.org/t/emails-are-not-threaded-in-outlook-2013/16501 "2014-06-13T04:36:40Z")
**Posts on this page:** 1
**Showing post:** 5

<div class="post-metadata">

### Author: ![codinghorror](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/codinghorror/32/110067_2.png) [@codinghorror](https://meta.discourse.org/u/codinghorror)
#### Post date: [June 13, 2014, 8:46pm UTC](https://meta.discourse.org/t/emails-are-not-threaded-in-outlook-2013/16501/5 "2014-06-13T20:46:38Z")

</div>

There are a lot of `List-` headers here:

```
List-ID: felixge/node-sandboxed-module
 <node-sandboxed-module.felixge.github.com>
List-Archive: https://github.com/felixge/node-sandboxed-module
List-Post: <mailto:reply+i-21866655-GUID-617481@reply.github.com>
List-Unsubscribe: <mailto:unsub+i-21866655-GUID-617481@reply.github.com>,
 <https://github.com/notifications/unsubscribe/617481__GUID>

```

The only one we have is

```
List-Unsubscribe: <http://discourse.specifiction.org/my/preferences>

```

We can certainly add these headers:

`List-ID`, `List-Archive`, `List-Post`

It looks like:

`List-ID` = topic title, e.g. URL fragment? `/t/topic-title/1234`  
`List-Archive` = topic URL  
`List-Post` = duplicate the email reply address

The difference in `Reply-To` could also help?

```
Reply-To: felixge/node-sandboxed-module
<reply+i-21866655-GUID-617481@reply.github.com>

```

versus

```
Reply-To: domenic <discourse+GUID@specifiction.org>

```

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