For reasons that at the moment I dont know :) , my service provider allow ftp passive access to a remote server only when the remote passive port range is within 50000-50500 range. I wonder: what is the port range of ftp.drivehq.com? May I customize it in any way, so that I can "force" it using a port in that range?

thanks

Sorry, no, you cannot force a passive port. For security reasons, it must be randomly selected.

In this case, please use DriveHQ FileManager, which uses HTTP / HTTPS, so you are not limited by your ISP. DriveHQ FileManager also has a lot of better features than regular FTP (e.g. group sharing and folder synchronization) and is generally much faster than FTP.