Rsync
Files.com does not provide an Rsync server. Use the Files.com CLI App or Rclone to synchronize local files with your site.
Command Line (CLI) App
The CLI App compares files at matching paths and skips files with the same size. It does not use Rsync's block-level comparison, and a content change that leaves a file the same size can be skipped.
Push files from a local Documents folder to a Files.com folder of the same name:
files-cli sync push --local-path="Documents" --remote-path="Documents" --send-logs-to-cloud
Pull files from Files.com to the local folder:
files-cli sync pull --remote-path="Documents" --local-path="Documents" --send-logs-to-cloud
See Synchronizing Files and Folders for dry runs, filters, and options for moving or deleting successfully transferred source files.
Rclone
Rclone's native Files.com backend supports copy and sync operations. A Rclone sync makes the destination match the source, including deleting destination files that are absent from the source. Review Rclone's examples and use a dry run before applying a sync.