OS mail problem

I have a problem - whenever I send email using OS Mail app, if the email contains an attachment which was place in the middle of the text, the receiver (on Outlook) will get only part of the email text (the part which is up to the attachment location), and the rest of the text will become a new attachment, in addition to the original attachment, so totally there will be one email with partial text, and two attachments (one is the original, and one new which is the rest of the text of the message)

Did anyone see this?

Any solution? (beside attaching the attachments to the end of the email)