Custom domain using Outlook.com – Send & Receive or Send As settings not working per my described configuration

I have a custom domain that I have configured to use Microsoft's Outlook.com / Hotmail.com e-mail services.

      My main issues include the Send & Receive from another email account and the Send As another account features.

   The set-up...

            I have two email addresses associated with my custom domain. These addresses are (using examples only)

                       *** Email address is removed for privacy ***  and  *** Email address is removed for privacy *** 

            I want to be able to check and respond to *** Email address is removed for privacy ***  messages when I am logged into *** Email address is removed for privacy ***

             I have already configured *** Email address is removed for privacy *** to forward to *** Email address is removed for privacy ***

             My problem is that I am unable to configure *** Email address is removed for privacy *** to send messages as *** Email address is removed for privacy ***

             I am also unable to configure *** Email address is removed for privacy *** to Send & Receive messages (via POP) from *** Email address is removed for privacy *** within the account settings.

Is this a bug that has not been fixed, or do I not have something configured correctly in my Domain Records?

Or, am I not using the correct POP3 & SMTP servers in order to make this configuration work properly?