Import Email From One Outlook.com Account To Another?

I'm new to Outlook.com. I created a user and set up a custom domain so I could add an existing email address to that domain. Due to the DNS changes to verify the domain, I couldn't figure out how to add an account to that custom domain and import email from that domain's old mail server (hosted on a regular linux webserver). The process to verify the domain would detached my ability to import to it. (Or is there a way to do that?).

So what I did is import the email from that custom domain email address into the Outlook.com account created first, before I added a custom domain. Now I am hoping to import that email across Outlook.com from one account to the other.

Is there a way to move email from one Outlook.com account to another? I tried half a dozen ideas and they all came up short. I'm stumped and hope there's a solution to the problem.

Thank you in advance for any help.

Regards,

Ansel Taft