What this feature does:

This is a security feature and it electronically ensures that your bank receives knowledge of all written checks from your account(s).

NOTE: Environment must be set as follows: DO_CBROUT=Y set in /etc/environment.

After this environment is set, and once you post payment batches, a file will be saved to disk.
(You can define where to place the file).
At that point, you are able to send that file to your bank for verification of written checks.