Transfer files between users of the same app with "cloud" storage

I am building an WPF app that need to exchange some very small xml files with other users. I'm currently looking into peer2peer networking, but I need the sender of the files to be able to send without the receiver being online also. I do not want to host a service myself, and I want the users to store the other users they interact with locally on their machine, for example just a开发者_如何学C name together with a GUID or email adress to identify them.

Do you guys have any suggestions on how to solve this? My wishful thinking would be if there was a free or cheap service where users could connect via my program to a public API and upload their files. And when the receiver user logs on, it would check the service and authenticate somehow, and download the XML files so it could be imported by the program.

I have made a solution with a IMAP library where the XML files are attached in the email and sent to the receivers email account. The program on the receiver checks the email and read the attachment. This works ok, but is not very slick and also filling up the users inbox and sent items with garbage..

Any suggestions is greatly appreciated.

Best regards Ola

This is one idea:

Normally, Block Storage volumes are seen as extra 'Drives' that you attach to a Virtual Machine. You could then use this but as if it was a metaphorical 'USB flashkey' that you would share with the other person.

1. Create the storage volume
2. Attach it to your VM and copy your data-to-be-shared on it
3. Detach the volume from your VM
4. Your Buddy, attaches it to his VM
5. He then copies the files and voila!

All this could be done through a web interface and you wouldn't have to do any networking steps.

All you need now is a capable Cloud Geek, a pot of coffee and some convincing.