Notify providers when tasks are due

Notify providers and project managers when tasks are due now or task deadlines are upcoming.

The sub-options are:

Check for due tasks every X hours
The frequency in hours at which MultiTrans checks for any due or upcoming task deadlines.
Notify Providers/PM of tasks due, X hours before delivery date (-1 to disable)
The time in advance of a deadline at which providers and project managers are notified. Enter -1 to send notifications only at the deadline.