How do I switch back to old outlook from new outlook?

Dear John DeMarche,

Good day! Thank you for posting to Microsoft Community. We are happy to help you.

Based on your description, I understand that you have a concern with “How do I switch back to old outlook from new outlook?”. We are looking into the issue, and before we proceed, we need more detailed information about the situation you are experiencing.

Please help us in isolating the issue by providing the following information:

1. Are you referring to new outlook Preview (PRE)? If so, you can revert back to "old" Outlook by toggling of the new Outlook or close outlook and open outlook by using outlook.exe instead of olk.exe. New Outlook is installed, and old outlook is still there, if the toggle switch is missing, you may go to Windows Start and search for Outlook, you will see both outlook, there is Outlook with PRE for new outlook in which you can open by olk.exe and the other outlook for the old in which you can use outlook.exe to open it.
2. If doesn't work, follow steps in this article, How to revert to an earlier version of Office (microsoft.com) to revert to the previous version of office:
   • Step 1: Set a reminder to enable automatic updates at a future date.
   • Step 2: Install the previous version of Office: Check and download the version you want from Update history for Microsoft 365 Apps for enterprise (listed by date)
   • Step 3: Disable automatic updates for Office.

We look forward to hearing from you, please let me know and provide a more detailed description so we can provide you with more specific assistance. Thank you for your cooperation.

Sincerely,

De Paul | Microsoft Community Moderator

Please see:

Toggling out of the new Outlook for Windows preview

Please see:

Toggling out of the new Outlook for Windows preview

when I goto outlook.exe it does not work. is there another method?

Dear John DeMarche,

Hope you are doing great.

Sorry to disturb. As we did not get response, may I know if above reply could clarify your issue, or could you please help to confirm if anything else we may help you with?

Thanks so much for your time and patience.

Sincerely,

De Paul | Microsoft Community Moderator