Hi Thomas,
Thank you for posting on the forum today. I’m Bambi, a user like you and I’ll be happy to assist you.
From what you’ve described, it appears you are trying to add a third party email to the New Outlook. However, the New Outlook is adding adaptability for third party email providers little by little, not all providers are supported at this time and even the supported providers have limited capabilities.
If it will be supported, I’m afraid I can’t say. But you could try again some other time and see if you are able to add it.
I hope this help. Let me know if there is anything else I can help you with.
Best Regards, Bambi