How to receive Subscription reports in Excel?

Hi guys,

I have set up many MQL reports to fire on Monday to the sales team.
All of them are set up to fire in format CSV (Excel 2007) - the weird thing is it opens in Excel for me but for 98% of our recipients it opens up in CSV file which leads to unnecessary manual work like converting the file and data management or screwed up phone numbers that won't format / convert.

Does anyone know if it's possible that these reports open up for others in Excel as well and how to achieve this?
I haven't done anything to make this happen for me, it just opens automatically in Excel and I have the 2016 version.

Thanks for your help!

Kim