Trying to send or retrieve a file over scp between an OpenSSH client and a SSH.COM SSH2 server won't work. The problem is that OpenSSH scp uses the scp/rcp protocol while the SSH.COM SSH2 server does not support that protocol anymore. SSH.COM scp2 client uses the sftp protocol to send and retrieve files (which works fine with OpenSSH servers). The solution for an OpenSSH client to transfer files with an SSH.COM SSH2 server is to use OpenSSH's sftp client. It is possible to use sftp in batch mode and I wrote an scp2 shell script that emulate the scp client. This script does not currently supports remote-remote file transfer nor multiple files at once.