Using Classic Outlook on Windows for personal email, calendar, and contact management
I have had the same issue and just fixed it. my setting was on "Rich Text", I changed to "HTML" and now my attached file no longer appears in body of email.
GO TO FILE IN OUTLOOK
CLICK ON OPTIONS
SELECT MAIL
UNDER 'COMPOSE MESSAGES', SELECT "HTML" IN RECTANGLE BOX JUST BEHIND:
Compose messages in this format: in drop down box select "HTML"