The 2 different ways Outlook reacts when hovering over the Outlook ICON

Question

The 2 different ways Outlook reacts when hovering over the Outlook ICON

Walter Van Eyck 20

Right now I seem to toggle unintentionally between the 2 versions

Classic: that offers me separate windows for open mails
New: That presents a list of open mails

How Can I easily select the version I want to use?

I could understand that once the open mails list becomes too long to profit of the clarity in the classic version reduces and the list need to be purged and outlook would change automatically to the new version. But I want to be sure.

Thank you for considering my question!

Walter

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Answer accepted by question author

TaoLi 110.9K Independent Advisor

Hi

From your description, I suspect you’re seeing Windows switch between thumbnail previews and a text list as more email windows are opened. This alone doesn’t mean you’ve switched between classic and new Outlook.

Try closing a few individual email windows, leaving just two open, then hover over the Outlook icon again. If thumbnails return, the change is related to the number of open windows. You don’t need to delete any emails.

To choose your Outlook version, search for Outlook in Start, then right-click the version you prefer and select “Pin to taskbar.” Microsoft explains this here: https://support.microsoft.com/en-us/outlook/getstarted/run-new-outlook-and-classic-outlook-side-by-side

Walter Van Eyck 20 Reputation points

2026-09-05T14:53:35.0033333+00:00

Hi TaoLi,Thank you for your intervention, your description matches exactly what I experienced this morning.

Looking back at my original question I admit to my poor wording. If I had written it as follows, AI might probably given me the same explanation as you did.

I could understand that once the open mails list becomes too long to profit of the clarity in the classic version, Classic Outlook switches to list the open mails instead of using the Thumbnails. After closing some open emails that I didn’t need, Classic Outlook returned back to thumbnails. ~~instead reduces and the list need to be purged and outlook would change automatically to the new version.~~ But I want to be sure.

Anyhow, your quick reply gives me the comfortable feeling that one is not left alone in its AI chats. I am also assured that I was all the time in Classic Outlook.

Thank you for playing short on the ball!

Kind Regards,

Walter

1 additional answer

Your answer

Walter Van Eyck 20 Reputation points

2026-09-05T14:53:35.0033333+00:00

Hi TaoLi,Thank you for your intervention, your description matches exactly what I experienced this morning.

Looking back at my original question I admit to my poor wording. If I had written it as follows, AI might probably given me the same explanation as you did.

I could understand that once the open mails list becomes too long to profit of the clarity in the classic version, Classic Outlook switches to list the open mails instead of using the Thumbnails. After closing some open emails that I didn’t need, Classic Outlook returned back to thumbnails. ~~instead reduces and the list need to be purged and outlook would change automatically to the new version.~~ But I want to be sure.

Anyhow, your quick reply gives me the comfortable feeling that one is not left alone in its AI chats. I am also assured that I was all the time in Classic Outlook.

Thank you for playing short on the ball!

Kind Regards,

Walter

Answer 1

The behavior described is consistent with switching between classic Outlook and new Outlook for Windows. The easiest way to choose which one to use is to launch the specific app directly, instead of relying on whichever Outlook session was last active.

Open the Windows Start menu.
Search for Outlook.
Choose the app explicitly:
- Outlook (classic) for the classic desktop app.
- Outlook for the new Outlook for Windows app.

If already in new Outlook and the goal is to return to classic Outlook:

Use the toggle in the upper-right corner.
Then choose either:
1. Switch back to classic Outlook to return to classic Outlook going forward.
2. Use classic Outlook this time to open classic Outlook only for that session.

If the goal is to use both during the transition, both versions can run side-by-side. A practical setup is:

Open one version from Start.
Pin both apps to the taskbar or Start.
Launch the one needed each time from its own icon.

Important details:

If classic Outlook is not installed, the toggle back may not appear.
If the toggle is missing with a work or school account, an organization admin may have disabled it.
To make sure the correct app opens, launch Outlook (classic) from the Start menu rather than the new Outlook app.

The provided information does not state that Outlook automatically changes from classic to new because the list of open mails becomes too long. The supported way to control the experience is by using the toggle or launching the specific app directly.