Lightroom :: How To Transfer Full-Resolution Images Without Risk Of Compression

In the past (but only once), I have used an online service that allowed me to zip a large amount of high-resolution images and upload them to their website in order to transfer them to another person (the other person would download the images at their convenience, within an allotted amount of time), while maintaining their full image quality.  I can't remember the name of this service, though.  I recall, that, in order to use it, I had to sign up for a free 14-day trial, so it is a paid service, although at the time, I only needed it once (or so I thought).