Dear SJ999
Thank you for using Microsoft products and posting in the community.Based on your description, I know there's a problem with your Outlook copy and paste function
No longer able to copy and paste email addresses - why?
I have been testing for a long time and have not encountered any issues like yours that cannot be replicated.
Can you go to the Outlook web page and check if the copy function is working properly?
https://outlook.live.com/
If you copy it to Notepad or Word first, can you copy it to New Outlook?
Finally, can you try uninstalling and reinstalling New Outlook.you contact Outlook. com through the following methods. They are also real people, not robots, just like us.
To get support in Outlook.com, click here or select Help on the menu bar and enter your query. If the self-help doesn't solve your problem, scroll down to Still need help? and select Yes.

TIPS: Please contact us during local working hours on weekdays. CHAT does not work 24 hours a day.
Thank you for your understanding and cooperation.Best regardsKokutou-MSFT |Microsoft Community Technical Support Specialist