The error message ECOM00209 translates to “Failed FTP upload: 550”
Error 550 usually denotes a permissions error. The FTP server at the client level is not allowing the credentials that it was passed to do what it was expected to with the file system. Please check whether the FTP user is allowed to read & write to the specified directory. It's also important to know if that user can delete files. Please also ensure that the destination path exists.