To make sure our service is as smooth and also as secure as possible, we create a zip files if you upload multiple files. It gives you the fastest upload possible, and the recipients an equally fast way of downloading the transfer. It doesn't matter what size the files individually are, it's just a fact that when you use our app to upload more than one file at a time a .zip file will be created.
Opening transfers (especially those larger than 4GB) is a feature that's proven to be difficult for the built-in apps of both old Windows versions and Mac. To open ZIP files larger than 4 GB, the program opening the archive needs to support Zip64 archives, and the built in solutions in Windows and macOS don't support this yet. They also struggle with localization/filenames.
The best way is to use Filemail Desktop to download files. This is way faster than web browsers - and automatically extracts all files for you. Simply install this application and copy/paste the URL to the download page into the app.
If you still need to unzip files - here is what we recommend:
On Windows we recommend using WinRar, which is free. It supports all common compression formats such as ZIP and RAR.
For Mac we recommend Keka - it's free and works a lot better than the built in Archive Utility on macOS.
After installing one of these apps, please ensure you open your zip file with this program and not the one already installed on your device.