Import Contact List

I use Outlook for mac with a 365 email account with my domain name.  I am trying to set up a "Contact List".  This is not to confused with my list of contacts.  The is a distribution list.  This feature is only pin New Outlook.

I have the names and email addressed in CSV format.  I tried to import.  The results say "No records imported" or "failed to import".  I have tried it with and without column headers.  there name format is First Last.

Sugestions appreciated.