Sorry for the confusion; we discovered some years ago that downloads barely larger than 2 GB were running into mysterious problems, but ultimately our sysadmin concluded those problems were in fact due to a server-side hard limit imposed by the maximum value a 32-bit signed integer can represent: 2,147,483,647, which in bytes is 2 GiB (2.147 GB). Thus, bypassing this limit would require a major, comprehensive overhaul of our system from 32-bit to 64-bit architecture.
Also bear in mind how long it would take to download files that large, considering that outside of major metro areas, broadband service may top out at only 1.5 Mbps or so:
Sellers with extremely large files to provide often use a disc-fulfillment service that can automatically duplicate and mail out data DVDs on-demand whenever an order comes in, rather than expecting buyers to babysit a download potentially for hours -- this help page lists the disc fulfillment services known to integrate with E-junkie:
Finally, if you still prefer to provide your product data as a download, we can recommend using us with the Continuata advanced download management service, which can support far larger files than we can, along with advanced features such as multi-part concurrent downloads that automatically reassemble into a single file upon completion, easy pausing/resuming of downloads in progress, and more. Integrating them with E-junkie is a simple matter of configuring your product with the "Send transaction data to a URL" option enabled, so you can paste the Payment Variable Information URL provided by Continuata into that product's settings, so we can notify them when the product is purchased. Find out more about Continuata here (see Products > Connect Downloader in particular):