Hi @Anonymous ,
You should be using a lookup to the user entity as a column in the Task to set the Accountable or Responsible user vs setting the email into the field. When you add the lookups to the User table on the Task table it will automatically create the referential relationship for you.
Now, restriction is a different situation... What you are doing here are adding lookups and you will not be able to drive security based on these lookups. To secure the tasks to be updated by only those users assigned as accountable or responsible you would need to setup an Access Team on the Task table and when you populate the lookups have this run a realtime workflow to add the users to the access team (or remove if you change the users).
By doing it this way then the security on the table will be setup correctly and you can utilize roles in the system to control updating of the tasks.
One more thing to think about is if you will ever have multiple "responsible" users that are assigned to the tasks. If this is the case you might want to consider adding a relationship table instead. You could create another table that is "User Task" that will have the owner set to the User, lookup to the Task, along with a field with two options "Responsible" / "Accountable". You can have this table setup as the following relationship.
In this model you could have multiple responsible or accountable users setup for the tasks or if you are going off the RACI model you could have roles for Consulted and Informed as well :). You would still need to utilize the Access Team to control updates to the Task itself.
Hope this helps, if so please mark Accepted Solution.
Thanks,
Drew
