Occasionally some of the supported sites can be a little temperamental and the submission fails due to some kind of server error. Most of the time they are fine.
The automatic reschedule feature will check why a submission failed and if it was due to a server error will reschedule the submission for the next day. If a submission fails 3 times it will be logged as a permanent failure.
This feature should increase the overall success rate of the submissions. Other errors are logged and investigated so improvements to the submission process can continually be made.