Hi.
It’s more than 6 years now on this topic. I think this feature is still not available on SuiteCRM.
I have created an installable module to do it. Of course, you have to change it as per your requirement but it will enable basic email notification where the task due date is equal to or greater than today.
You can download it from here Send a daily email reminder of pending tasks in SuiteCRM - SpecScale
Once you install the package from the admin panel you will see this schedule.
Here is the email you will get:
We haven’t used any third-party service or plugin. We are doing it by simply adding a custom scheduler.
Please feel free to contact me if you need any help.
Prafull