Your presumption is correct: unless
nsadmin is in your
mail group, as long as the file is not world-readable then AOLserver won't be able to open the file. You have three options: either make the file world readable (
chmod o+r teamlist), add the
nsadmin user to the
mail group, or create or reassign the group ownership of the file to a different group that
nsadmin is a member of.
I'd go with the first unless there is a compelling reason not to.