Source: Firefox Send
Firefox Send is another way to share files with a group of students or other staff members. Files can be shared to a maximum of 100 downloads or 7 days if you are signed in with a free Firefox account. Non-signed in users can share a file up to 1GB to 1 person or for 1 day.
I’ve had user issues sharing files through Google Drive, where the recipient couldn’t figure out how to actually download the file. Firefox Send would be a good solution in those situations, or for times where Google or Microsoft products aren’t allowed to be used by the recipient.