I was trying to use drivehq to store some backups that are about 200mb, but I see it stops to 50mb,  so there is no way a free true account is able to send files larger than 50mb? 

Hi, it pauses at 50 mb but you can continue by pressing the continue button.  Please use our file manager software to do your transfers.  Other restrictions can be read about here: http://www.drivehq.com/Premium/default.aspx

But how can you press continue button when the upload is done by server? the backups are stored on another server and I want to send them to drivehq ftp throughout the server itself so I can't use the software and I can't press the continue button, am I right?

The free service is designed for personal and casual use only. If you use it to backup your server, or if you use it with any automatic software / scripts or devices, you need to order our premium service, which starts at only $1.99/month.