How can I download all attachements at once ?

How can I download all attachements at once ?
And find them e.g. named in folder according to e.g. the names of the senders,

or any other parameter ?

You can download all the attachments on the form's submissions (sheets) page. Here's how:

1. Select a form in your My Forms page then click the Submissions button

2. In the Sheets page, click the Download All button then Download All Uploads. This will send you an email containing the link to download the zip file.

I think the files are segregated with folders named from the full name field values or the submission IDs if the full name doesn't exist in your form.