You can use the job queue to create a multi-step action to execute on the target. You can use the special item in the job queue ‘Send email notification if previous action fails/errors’ to trigger an email to be sent.
So for example your job queue could be:
1. Download and install updates + reboot if required
2. Send email notification if previous action fails errors
Other options for sending email notifications are explained here:
using-email-notifications-to-check-status-of-automated-patching-events