Automatic action for Synchronizing already imported users

I am often required to synchronize my imported users manually to update first/last names, email or photo from AD to GLPI.

Could this be an automated task like mailgate in which a number of existing users could be automatically synchronised outside of business hours? As an example I might run the task from 00:00 to 04:00 every 5 minutes and synchronize 50 user at a time.

This automated action would reduce our need to perform the action manually.