I want to have an app automatically check a column after a certain period

[Aldrin_Nyamweda]

I have been looking through the community but I haven’t been able to find anything that is helpful. How do I go about this. I want the app the check the column for an email address in one table while it refers to the other table that has the list of staff. I want this to happen automatically. If there’s an article I missed. Please kindly link it. Thank you