This is a first part of the task that I received from n26. It includes Batch Apex class which queries Contacts for notification and update. I limited query with 5000 records since there is a limit on the amount of emails that could be sent from Apex class a day. But the better solution would be a custom setting that has a field which would be refreshed every day and to use that custom settings throught all Apex classes to not exceed existing limit.
Unfortunately I wasn't able to finish the second part of the task where I should have create a lightning component. I have to admit that I underestimated my skills in Lightning components.