getTargetDeliveryWindow() {
        const targetDeliveryWindow = this.#config.get('bulkEmail')?.targetDeliveryWindow;
        // If targetDeliveryWindow is not set or is not a positive integer, return 0
        if (targetDeliveryWindow === undefined || !Number.isInteger(parseInt(targetDeliveryWindow)) || parseInt(targetDeliveryWindow) < 0) {
            return 0;
        }
        return parseInt(targetDeliveryWindow);
    }
Returns the configured target delivery window in seconds
Ghost will attempt to deliver emails evenly distributed over this window

Defaults to 0 (no delay) if not set

@returns {number}