I use Photoshelter, but it's not free.

This is a referral link but it gives you a discount, too, if you want to use it http://www.photoshelter.com/referral/PA5CX7F75K

I don't remember what the basic cost is but when I had problems with bandwidth I thought it was well worth it for all the time it saved me. You can also try using your website there to make direct sales if you can receive Paypal or have a merchant account.

It may well not be right for you, but you can take a look.

I upload, then click on FTP and I've got everything set up for direct transmission to most agencies. Istock doesn't take it of course, and 123s FTP doesn't seem to work.

Afterwards, I transfer the files from the upload folder to a subject folder - such as a place - to make it easy to find them later.

picworkflow does exactly that. There is actually no service that will submit your photos from the cloud, the only service that submit your photos is stocksubmitter but it does it direct from your computer.