Sharing files and information for collaboration should be easy. It's not.

Attachments get blocked by email servers. Spam filters nail your message. Edits come back to you in some unreadable format.

Multiple versions of documents lead to confusion. Files are too big to email. You leave your email client running at work and can't access the files from your home computer.

You might consider SharePoint or web based file storage, but it's not worth the effort for a short project. You'd have to train everyone to use it and get them to create accounts, and it's only a two week project. (Well, you THINK it's only two weeks.)

Your organization has a large collaboration package, but by the time you navigate the IT department to get everything set up, your project will be over.

So you stick with email.

You don't have to any more.