---
title: What's missing in New Outlook and what to do about it
description: What new Outlook for Windows still does not do as of September 2026, taken from Microsoft's own feature list, and how to plan around each gap.
---

[Vonian Writing](https://vonian.net/blog)

# [What's missing in New Outlook and what to do about it](https://vonian.net/blog/whats-missing-in-new-outlook)

 Written by [Vonian](https://vonian.net/blog/author/vonian) | Sep 27, 2026, 12:18:29 AM

Microsoft is moving Outlook for Windows users to New Outlook in stages. In the first stage, users choose to try it; in the second, New Outlook is on by default and users can still switch back; in the last, called cutover, they cannot. Microsoft says administrators get at least 12 months' notice before each of the later stages, and that existing installations of classic Outlook will continue to be supported until at least 2029 ([Microsoft Learn: stages of migration](https://learn.microsoft.com/en-us/microsoft-365-apps/outlook/get-started/guide-product-availability)). Nobody has to switch this week, but the direction is settled.

It helps to know what New Outlook is. Microsoft describes it as a native application built on WebView2, where the experience is provided by Outlook on the web and a thin Windows integration component gives it access to local files and resources ([Microsoft Learn: overview of the new Outlook for Windows](https://learn.microsoft.com/en-us/microsoft-365-apps/outlook/overview-new-outlook-windows)). That explains many of the gaps: things classic Outlook did by letting code run inside the program, such as macros and COM add-ins, are not part of that design.

This article covers what is missing as of September 2026, how to find out which of those gaps actually affect you rather than somebody on a forum, and what to do about each one. Microsoft keeps a [feature comparison between new and classic Outlook](https://support.microsoft.com/en-us/office/feature-comparison-between-new-outlook-and-classic-outlook-de453583-1e76-48bf-975a-2e9cd2ee16dd) and changes it regularly, so treat any list, including this one, as a starting point and check anything critical against the current version in your own tenant.

## The gaps that come up most

The statuses below use Microsoft's own wording from its feature comparison, last updated 23 September 2026.

- VBA macros: Not supported. Macros do not run.
- COM add-ins: Not supported. Web add-ins are supported instead.
- PST files: Partially available. You can import mail from a PST, open one and export to one, with conditions (below).
- Rules: Partially available. Client-side rules from classic Outlook are not processed; rules import and export is not supported.
- Dragging files to the desktop: Available (since January 2026). Dragging to other applications is listed as upcoming.
- Offline support: Partially available. Works, with less than classic.
- Shared mailboxes: Available. Delegate access is partially available.
- Quick Steps: Partially available. Present, not every classic option.
- Admin policy: Exchange PowerShell and Cloud Policy. Most mailbox policies apply to both Outlook on the web and New Outlook ([Microsoft Learn: policy management](https://learn.microsoft.com/en-us/microsoft-365-apps/outlook/manage/policy-management)).
- Third-party desktop integrations: Depends on the vendor. The vendor has to ship a web add-in.

One clarification, because it gets reported wrongly. Several of these have changed in the last year, and PST support, drag to desktop, offline support and delegate access all have 2026 updates on Microsoft's list. A complaint written in 2023 is not evidence about the client you would install today. If your objection to New Outlook is based on something you read a while ago, test it before you plan around it.

## The four that actually change a working day

### VBA and COM add-ins

If anyone in your organisation wrote a macro, or you use a practice management, CRM, document management or dictation tool that installs an Outlook toolbar, that is the migration. Everything else is smaller. COM add-ins are not supported in New Outlook and cannot be switched on by a setting; the vendor has to have built a web add-in ([Microsoft Learn: migrate from COM add-ins to web add-ins](https://learn.microsoft.com/en-us/microsoft-365-apps/outlook/get-started/migrate-com-to-web-addins)). For smaller vendors and internal tools, often nobody has.

What to do: list every add-in in classic Outlook now, before anyone upgrades, and contact each vendor for its web add-in status with a date attached. The answers you get will sort your users into those who can move immediately and those who cannot move at all yet. That list is more useful than any feature comparison.

### PST files

PST support in New Outlook is better than its reputation, but still narrower than classic. You can import mail from a PST into a mailbox, open a PST to browse it, and export mail to a PST. Opening a PST has conditions: classic Outlook must also be installed, both must be the same 32-bit or 64-bit architecture, the account needs a Microsoft 365 subscription, and it does not work on the ARM version of New Outlook. Calendar and contact items in PST files are not available in New Outlook yet ([Microsoft Support: import from a .pst file](https://support.microsoft.com/en-us/outlook/import-email-contacts-and-calendar-from-an-outlook-pst-file); [export to a .pst file](https://support.microsoft.com/en-us/outlook/export-emails-contacts-and-calendar-items-to-outlook-using-a-pst-file)). For most people this only matters twice, when they want an old archive and when someone leaves. Neither is frequent, and both are real.

What to do: move the content into the mailbox rather than depending on the client to read the file. Import the PST into the mailbox, or into an online archive if the mailbox is close to its quota. Doing this while classic Outlook is still installed is easier, because opening a PST in New Outlook depends on classic being there too, and PST calendars and contacts still need classic.

### Client-only rules

Microsoft says some rules created in classic Outlook cannot be processed by New Outlook because they are client-side rules, and the fix is to create a new rule to replace each one ([Microsoft Support: manage email messages by using rules](https://support.microsoft.com/en-us/office/manage-email-messages-by-using-rules-in-outlook-c24f5dea-9465-4df4-ad17-a50704d66c59)). Rules in New Outlook run in the mailbox, which is better in one way, since they run whether your machine is on or not, and worse in another, since they cannot do everything a client-side rule could.

What to do: open Rules in classic Outlook and look for the ones marked client-only. Some can be recreated as mailbox rules with a small loss. Anything that depended on your computer, such as starting an application, cannot, and has to be replaced with a different approach.

### Dragging messages out of the mailbox

Dragging a message onto a network folder, a case file or the desktop to keep a copy is common in legal, engineering and property work, and it is the one people complain about loudest. Microsoft now lists dragging files to the desktop as available in New Outlook, since January 2026, and dragging to other applications as upcoming. You can also save a message as a file to a folder on your computer from the Save as menu ([Microsoft Support: save a message as a file](https://support.microsoft.com/en-us/outlook/mail/save-an-outlook-message-as-a-eml-file-a-pdf-file-or-as-a-draft)). Dragging between mail folders inside the mailbox is a separate thing, which is worth separating out, because the two complaints get merged in search results and they are not the same problem.

What to do: if filing email onto a file share is part of how the business keeps records, test it specifically, on the version you will deploy, with the file format your records system expects, before committing to a date. If it does not work well enough, the options are a document management system with a supported web add-in, or keeping classic Outlook for the affected team while it remains supported.

## Work out your own gap list

A published comparison tells you what is missing in general. It does not tell you what is missing for you, and the difference is usually large. A faster method:

1. Take the ten things you do most in Outlook in a normal week. Write them down as actions, not features.
2. Do each one in New Outlook on a real mailbox, not a test one.
3. Note what failed, and separate "different and I will get used to it" from "cannot be done".
4. Check anything that failed against the current Microsoft documentation, since some of it will have been fixed since whatever you read.

Most people find two or three genuine blockers and a longer list of things that are merely unfamiliar. Planning around the first group and ignoring the second is the whole job.

## The part that does not get better either way

Filing is the exception to everything above, because filing was already the unglamorous part of a mailbox before the client changed. Nothing in New Outlook makes it worse and nothing makes it better. Messages that should be in a matter folder, a client folder or a project folder sit in the inbox because moving them is a decision plus several clicks, and the person who has to make that decision is busy. Then somebody needs the message eleven months later and cannot find it.

Rules handle the mail that is predictable. The mail that is not predictable, which is most of the mail that matters, comes down to a person deciding where it goes.

This is the problem we are building ClickSort for. It is an Outlook add-in that learns from the messages already in your folders and suggests where a new one belongs, so filing becomes accepting a suggestion rather than navigating a folder tree. It is a web add-in for New Outlook for Windows and Outlook on the web, with a Microsoft 365 work or school mailbox. The [demo](https://vonian.net/demo) on this site uses sample messages and connects to no mailbox, and the current plans, including a free tier of five filings a day after a 14-day trial, are on the [pricing page](https://vonian.net/pricing). The prediction runs on your device rather than on our servers, and the [security page](https://vonian.net/security) sets out exactly what does and does not leave your machine, including the things that do.

## What to do this month

Audit your add-ins, deal with your PST files while classic Outlook is still installed, review your client-only rules, and test the drag-to-file behaviour if anyone in the business relies on it. None of that is urgent in September 2026. All of it is much cheaper now than in the month you are told the migration is happening.

[View full post](https://vonian.net/blog/whats-missing-in-new-outlook)

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