Dear Lionel Worman,
Good day! Thank you for posting to Microsoft Community. We are happy to assist you.
Based on your description, you want to know how to manage the distribution list as an owner in Outlook Web client.
For this issue, I did some research and test, please follow the steps below to edit your distribution lists:
- Login to your Outlook Web via https://outlook.office.com/.
- Click the Settings icon
at the right-top corner. Click View All Outlook settings.
- Click General-Distribution groups. You will see the distribution lists which you belong to, and you own, like the screenshot below:
- Click Edit icon
under the distribution groups you own, you will be able to manage the distribution list membership as an owner.
I hope the information above is useful for you. If there is any update or I misunderstand you, please feel free to let me know. I will continue to assist you. Your understanding and co-operation are highly appreciated.
Thanks for your precious time. Have a nice day!
Sincerely,
Sherry | Microsoft Community Moderator