Depending on CPU execution time, browser limitations, and AppExchange features you can download up to 2000 files/Attachments in one click.
Using pagination in a second click you can download the other 1000 files/attachments making you download the bulk of files & attachments using the Mass File Download app.
Follow the below steps:
- Go to Mass File Download Tab --> Select the Related files & Attachments sub-tab.
- Select Object and Search Mode then click on Search Button.
- Click on the Show drop-down and select 2000, Now you can see 2000 files & Attachments at a time.
- Using pagination 1,2,3,4, and so on, you can download your Files & attachments.