AWS News Blog

Size Does NOT Matter!

Size does not matter anymore!

Podmail_3 zSlide, privately held company in France, just released a new “express” feature in its service. is simple P2P-based email service that enables anyone to send and receive e-mails with attachments up to 2GB. 2GB!! did you read that?!. Wow! Last I knew, Internet world changed when email giants increased the inbox size to 2GB. And now each email attachment can be up to 2GB in size.

Podmailer Express, powered by Amazon S3, says:

Today introduces a new feature called “Podmail Express” which assures a fast and reliable delivery in every situation, for files up to 2GB. The files in transit are stored on a highly scalable infrastructure that we have built on top of the Amazon S3 web service.

“We create the simplest applications based on Peer-to-Peer technologies in order to provide unskilled users with the most efficient services”, says Louis Choquel, CEO of zSlide. “To solve the issue of quality of service, introduces a new breed of Peer-to-Peer services. Our idea is to support our Peer-to-Peer network with a rock-solid and highly scalable infrastructure that can grow in symbiosis with it. It has become a reality thanks to Amazon S3.”

As I did more research, I started to learn more and more about Podmailing. I installed the windows client and played with it. They have embedded the power of BitTorrent in emails to deal with big attachments. Damn! Why-did-I-not-think-of-this-idea-first ?. Most interesting part was when I realized how creatively they solved their technical problem and how Amazon S3 was a just a perfect fit for them. Here’s how…

Podmailing is email++

Instead of including the attachment into the e-mail, they use the BitTorrent protocol in order to transport the file (P2P fashion). So the file can be of any size, and if there are several recipients they all contribute to the delivery of the file between each-other. Smart, isn’t it?. They do this by simply embedding a small “link file” as attachment into the e-mail which contains all the cues needed to transport the data. This “link” is similar to a “.torrent” file with some extra info (proprietary “.zed” extension)

The Problem

The downside to this type of P2P system is that the sender and the recipient must be online at the same time for the file to be transfered.

The Solution

Smart Guys at zSlide decided to use Amazon S3. Now that I think of it, I get that made-for-each-other feeling just like what we get when we see a happy cozy couple walking in the park hand-in-hand. Let me explain why I think its made-for-each-other:

Amazon S3 is used as a relay to store the big attachments in transit.


  • The upload can start right away even if the recipient is not connected.
  • Because of server-based relay, the transfer becomes possible even if the sender and the recipient are blocked behind firewalls.
  • Once the upload to Amazon S3 is completed, the sender can turn off his PC and be sure that the file will be delivered in a fast and reliable way.
  • Because Amazon S3 is already supporting BitTorrent OOTB, they can still benefit from the network effect of P2P. So if there are many recipients, or if the e-mail is forwarded many times to many people, each user will contribute bandwidth to others.

And this is how Amazon S3 has started to change people’s lives :)

— Jinesh

Jeff Barr

Jeff Barr

Jeff Barr is Chief Evangelist for AWS. He started this blog in 2004 and has been writing posts just about non-stop ever since.