How to Thread Emails in Outlook (Conversation View, 2026)
Email threading collapses every reply, forward, and re-reply that shares a subject line into one expandable item in your message list. Microsoft calls it Conversation View or Show as Conversations. Instead of fifteen separate rows for one back-and-forth, you get one row you can open to read the whole exchange in order. The toggle sits in a different place in each version of Outlook, so here’s how to turn it on, sort it, expand it, and turn it off in all of them.
What threading actually does
Outlook groups messages into a conversation when they share the same subject and belong to the same reply chain (it reads the hidden conversation ID and references that email clients attach to every reply). When threading is on:
- The whole exchange shows as one row, usually labeled with the number of messages inside it.
- Clicking the row expands the thread so you can read each message in sequence.
- New replies bump the entire conversation to the top (or bottom) instead of scattering across your inbox by individual timestamp.
- Threading spans folders: by default a conversation can pull in your own replies from Sent Items and related messages from other folders, so you see both sides in one place.
The trade-off: messages get grouped by subject, so two unrelated emails that happen to share a subject line like “Re: Update” can land in the same thread, and a single noisy thread can hide newer mail underneath it. The settings below let you tune that behavior.
1. New Outlook Desktop & Outlook on the Web
The new Outlook for Windows and Outlook on the web share the same interface, and threading is on by default in both.
Toggle it from the View tab
- Open new Outlook or go to outlook.office.com.
- Click the View tab in the ribbon.
- Click Conversations.
- Choose Group into conversations to turn threading on, or Show each message separately to turn it off.
Toggle it from Settings
- Click the Settings gear in the top-right corner.
- Go to Mail > Layout.
- Under Message organization, choose Show email grouped by conversation (or Show email as individual messages to turn it off).
- Under Arrange the reading pane, pick Newest on top, Newest on bottom, or Show each message separately.
The reading-pane setting controls whether the most recent reply appears at the top or bottom when you open a thread. Newest on top matches how most people scan.
2. Classic Outlook for Windows
Classic Outlook (the MSI/Click-to-Run desktop app that pre-dates the new Outlook) keeps threading on the ribbon as a checkbox.
- Open classic Outlook.
- Click the View tab on the ribbon.
- In the Messages group, check Show as Conversations.
- When prompted, choose All mailboxes to apply threading everywhere, or This folder to apply it only to the current folder.
Fine-tune with Conversation Settings
On the same View tab, click Conversation Settings for four options:
- Show Messages from Other Folders — pulls in related messages stored elsewhere, including your replies from Sent Items, so you see the full back-and-forth.
- Show Senders Above the Subject — puts sender names at the top of each conversation instead of the subject line.
- Always Expand Selected Conversation — keeps the conversation you click open instead of collapsed.
- Use Classic Indented View — indents each reply to show its position in the chain, like an old-school threaded view.
Tip: Threading in classic Outlook is set per folder unless you chose All mailboxes. If only your Inbox is threaded and other folders aren’t, re-run the toggle and pick All mailboxes.
3. Outlook for Mac
Classic Outlook for Mac
- Open Outlook for Mac.
- Click the Organize tab in the ribbon.
- Toggle Conversations on (or off).
New Outlook for Mac
- Open the new Outlook for Mac.
- Go to the View menu in the macOS menu bar and click Show as Conversations, or open Outlook > Settings > Reading to set conversation and reading-pane order there.
The setting applies across your folders and accounts in the app.
4. Outlook Mobile (iOS and Android)
The mobile apps call threading Organize mail by thread (sometimes shown as Group emails by conversation), and it’s on by default.
- Open Outlook on your phone.
- Tap your profile picture or account icon in the top-left corner.
- Tap the Settings gear.
- Scroll to the Mail section.
- Toggle Organize mail by thread on or off.
On iOS you can also tap Email Organization to set Arrange the reading pane to Newest on top or Newest on bottom. The change applies to every account in the app.
Expand, collapse, and read a thread
Once threading is on, each conversation behaves like a folder of messages:
- Expand a thread: click the chevron (the small arrow/triangle) to the left of the conversation, or click the conversation row itself.
- Collapse it: click the chevron again.
- Read one message: with the thread expanded, click any individual message to open just that reply in the reading pane.
- Select the whole thread: click the top conversation row. Actions like Delete, Archive, Categorize, or Move then apply to every message in the conversation at once.
If your threads only ever show the latest message and won’t expand to reveal the rest, that’s usually the reading-pane order or a partial-conversation display setting. See the fixes below.
Turn threading off
Use the same control you used to turn it on:
- New Outlook / Web: View > Conversations > Show each message separately, or Settings > Mail > Layout > Show email as individual messages.
- Classic Outlook for Windows: View tab > uncheck Show as Conversations.
- Outlook for Mac: Organize tab > toggle Conversations off (classic), or View > Show as Conversations (new).
- Outlook Mobile: Settings > Organize mail by thread toggle off.
With threading off, every message becomes its own row sorted by date. That’s handy when you need to act on individual replies or hunt for one specific message in a long chain.
Common threading problems
“Show as Conversations” is missing or greyed out. In classic Outlook the checkbox only appears when your message list is arranged by Date. Click the column header (or View > Arrange By) and switch to Date to make it reappear. The option is also unavailable on some IMAP/POP accounts.
Threads only open partway. If a conversation shows the newest reply but hides the earlier ones, turn on Show Messages from Other Folders (classic) or check that the reading pane is set to show the full conversation rather than a single message. Replies you sent live in Sent Items, so without cross-folder display the thread looks incomplete.
Unrelated emails are grouped together. Outlook groups by subject, so messages with identical subjects (“Re:”, “FYI”, “Update”) can merge. Renaming the subject when you reply, or turning threading off for that one folder, separates them.
A thread keeps jumping to the top. That’s threading working as designed: any new reply re-floats the whole conversation. If a noisy thread is burying newer mail, mute or Ignore the conversation (right-click > Ignore) to send it and future replies to Deleted Items.
Quick reference
| Version | Where to toggle | What it’s called |
|---|---|---|
| New Outlook Desktop | View > Conversations, or Settings > Mail > Layout | Group into conversations |
| Outlook on the Web | View > Conversations, or Settings > Mail > Layout | Group into conversations |
| Classic Outlook for Windows | View tab > Show as Conversations (+ Conversation Settings) | Show as Conversations |
| Outlook for Mac (classic) | Organize tab > Conversations | Conversations |
| Outlook for Mac (new) | View > Show as Conversations, or Settings > Reading | Show as Conversations |
| Outlook Mobile (iOS/Android) | Profile > Settings > Mail | Organize mail by thread |
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