Sorting your inbox by size or deadline in the new Outlook has always had a blind spot: Outlook would reorder the list, but never show you the value it was sorting on. On Microsoft 365 Roadmap ID 564803, Microsoft is fixing that. Starting in June 2026, new Outlook for Windows and Outlook on the web will automatically add a column whenever you sort by a field other than From, Subject or Date Received — so sorting by size shows a size column, and flagged mail can finally be lined up by due date. It’s a small feature, but it’s the kind that quietly makes inbox triage faster.
What’s changing in the message list
When you sort the new Outlook message list by any field other than From, Subject or Date Received, Outlook will now surface an extra column showing that value — Size, Category, Importance or Flag Due Date. Sort by Size and a Size column appears next to each message; sort by Flag Due Date and the deadlines display inline. The update is tracked as Microsoft 365 Roadmap ID 564803 for new Outlook for Windows and Outlook on the web, with general availability in June 2026.
Until now, the new Outlook let you choose a sort order but kept the sorting value hidden, so a list arranged by size looked identical to one arranged by date — you just had to trust the order. As Neowin puts it, it’s a simple but very useful change. Windows Report and M365 Admin add the detail that matters most for people who flag mail: sorting by Flag Due Date is now supported, with the due date shown as its own column. Classic Outlook has long let power users add and drag columns by hand; this brings that visibility to the stripped-down interface that’s steadily replacing it.
Why it matters for your inbox
If you triage email by anything other than date, this removes a real friction point. Clearing space by sorting on size now shows you each message’s size; managing follow-ups by flag now lines them up in deadline order. You stop guessing why the list is ordered the way it is, and you stop building custom views to see it.
The practical wins are everyday ones. Hunting for the giant attachments eating your storage quota? Sort by size and the size column tells you instantly which threads to delete first — the same housekeeping that matters more now that providers keep trimming free storage. Living out of flagged email as a to-do list? Sort by Flag Due Date and your follow-ups queue up by deadline instead of arrival time. It pairs naturally with the inbox-organization tools Microsoft has been shipping for the new Outlook this spring, like the External sender tag in inbox rules. None of this is dramatic — there’s no AI, no redesign, no price tag. It’s Microsoft closing a small usability gap in the new Outlook it’s pushing everyone toward, and for once the fix is exactly what users asked for: just show me the column I sorted on.
Alexis Dollé, email expert for 10+ years. Founder of Email Tools. I test every email client and utility myself, then write about them the way I’d explain them to a friend — no marketing fluff, no sponsored rankings, every claim sourced.
LinkedInFrequently asked questions
What is changing in the new Outlook message list? — a sort column appears for size, category, importance and flag due date
When you sort your mail by a field other than From, Subject or Date Received, Outlook will automatically add a column showing that value. Sort by Size and a Size column appears; sort by Flag Due Date and the due dates show inline. The change is listed under Microsoft 365 Roadmap ID 564803 for new Outlook for Windows and Outlook on the web, rolling out in June 2026. You no longer have to guess why messages are in the order they are, or hand-build a custom view to see it.
Which Outlook versions get this? — new Outlook for Windows and Outlook on the web
The roadmap entry names new Outlook for Windows and Outlook on the web. Classic Outlook for Windows already lets you add and rearrange columns manually through its view settings, so this update is about bringing that visibility to the newer, simpler interface that has been replacing it. There is no mention of the iOS or Android apps in the roadmap item.
When does it roll out? — June 2026, in waves
Microsoft lists general availability for June 2026, and coverage from Neowin and Windows Report describes it beginning to roll out this month. Microsoft 365 features arrive in waves, so the exact day you see it depends on your account and release channel — it may appear over a few weeks rather than all at once.
Can I sort flagged emails by their due date now? — yes, that’s one of the headline additions
Yes — that is one of the headline additions. Sorting by Flag Due Date lets you line up the messages you have flagged for follow-up in deadline order, which is genuinely useful if you use flags as a lightweight to-do list. The due date appears as its own column once you sort by it.
Why does seeing the sort column actually matter? — a sorted list without the value is confusing
Because a sorted list without the sorting value is confusing. If you sort by size to clear space but can’t see each message’s size, you’re working blind. Surfacing the column turns a hidden sort into a visible, scannable list — the same reason spreadsheets show the column you sort on. It is a small change that makes inbox triage faster.
Sources
- Microsoft 365 Roadmap — “Outlook: Sort improvements to the message list”, Feature ID 564803 (primary: when the Sort By field is not From, Subject or Date Received, an additional column is shown for the sort value e.g. Size; sorting by Flag Due Date added; new Outlook for Windows and Outlook on the web; general availability June 2026)
- Neowin — “New Outlook for Windows and Web is getting a simple but very useful email feature” (independent: automatic extra column showing the sort value; sorting by a field other than From/Subject/Date Received; rollout this month; Flag Due Date especially useful for follow-up management)
- Windows Report — “Outlook is Getting Message List Sorting with Dynamic Columns & Flag Due Date Support on Windows & Web” (independent: dynamic columns when sorting; Flag Due Date support; Windows and web)
- M365 Admin (handsontek.net) — “Outlook: Sort improvements to the message list” (independent: Size column on sort-by-size; category surfaced when sorting by category; Roadmap ID 564803; June 2026 GA)