voice files in outlook no longer downloading

I am sending emails with a GarageBand voice recording of up to 60 min through Mail Drop to another Mac user in same residence. We both have Outlook. Since latest Microsoft problems the files will no longer open in outlook mail. I send the files on a newer Mac notebook used primarily for recording. I can receive files on the email on that notebook and test them in the app in the mail but they are sending but not opening on other Macs in household.