Hi Eugene,
@George, thanks for your reply.
Based on the description and the DNS records that provide, I found that the TXT/MX record hasn’t been added to your domain register when you verified domain.
Please try to refer to the following link to verified domain:
For professionals and Small Businesses: onlinehelp.microsoft.com/.../gg584174.aspx
For Enterprises: onlinehelp.microsoft.com/.../gg584188.aspx
Thanks,
Anna Shi