Groups.io provides a Files feature that members can use to upload and view files on a group’s website. Files can be organized in folders. 

A group’s Files section can also contain links to files that are stored in external locations such as Dropbox and Google Drive as well as links to other websites.

Note:

• Group owners determine whether the Files feature is available in their groups and, if it is, who can view and upload files: all members or only owners and moderators.
• The size limit for an uploaded file is 2GB.

Emailed Files

Files attached to group messages are listed in Emailed Files, which appears first at the top level of Files for members who can also see the group's message archive. Emailed Files is a view of the message attachments, not a folder: you can't upload to it, rename it, or move it.

• Images are not listed unless you select Include images. They are shown in the Emailed Photos album.
• You can search Emailed Files by filename, filter it by sender, and sort it by date or filename.
• Deleting an attachment from Emailed Files removes it from its message. Members can delete attachments from their own messages; moderators with the Edit Archives permission can delete any attachment.
• To keep an attachment separately, click its Copy button and choose a folder. The copy is an ordinary file, owned by you, that stays if the message or the attachment is deleted. It shows which message it came from and who originally posted it, and it uses Files storage like any upload.