Plugin to automate shrinking media images?

I have a client who has staff that I recently discovered has been uploading original sized, print quality images to her site for some time instead of shrinking down in the interest of space….and I am thinking this may be why her backups time out on me every single time. Her site doesn’t have tons of pages, but there are a LOT of images. And now that I know they have been uploading full size images, like mostly 2 and 3000 pixels wide and sometimes larger (many are professional photographer shot) …that could be what would make backups stall, right?

Anyway…my question is…because I know that WP saves a copy of the original if you edit within WP, I know that editing within isn’t the answer…and that removing the images and reuploading would be a HUGE job….so is there a reliable plugin to automate this process?

My next question….Is there a plugin that would automatically shrink these images to a reasonable size upon upload in the future? I know she will get new staff from time to time that will forget or not get the concept…and even though I’ve now explained how to upload via the iPhone app and how you can set that to upload to a smaller size that way….I know that many of them will still upload using a computer and thought it would be ideal to have something in place to just avoid the issue. I don’t see sending them all to PicMonkey to edit every image as working for everyone. Some will, some won’t. There has to be an easier way.

Any suggestions?

Thanks in advance!!