I’m trying to automate sending an email via Outlook from Python using win32com.client, but Outlook COM fails to start with “Server execution failed / Operation unavailable”.

The error occurs before any email object is created, so it’s not related to recipients, attachments, or message content.
Environment

• Windows 11

• Python 3.14

• pywin32 installed

• Microsoft Outlook installed (New Outlook UI enabled; classic Outlook may also be present)

  What I’ve already tried

  • Running the script from a .py file (not Jupyter / notebook)

  • Opening Outlook manually before running the script

  • Killing all OUTLOOK.EXE processes and retrying

  • Using both Dispatch and DispatchEx

  • Calling pythoncom.CoInitialize()

    Questions

    1. Is Python 3.14 compatible with pywin32 and Outlook COM automation?

    2. Does the New Outlook app prevent Outlook.Application COM automation even if classic Outlook is installed?

    3. Is this a known limitation or environment issue with recent Python versions?

    Any guidance on whether this is a Python version issue, Outlook version issue, or a Windows/COM limitation would be appreciated.