Hi Markus,
If you haven’t already, set up a field in your Employees table that tracks how long they have been with the company, then create a view that filters where the ‘# of Days’ field is greater than 85 or alternatively, set the filter to where the start date is more than 85 days ago.
Once you have that set up, create an automation where your trigger is ‘When a record enters a view’, select the new view you just set up.
Then for your action, you can set up an email to be sent to whatever email you’d like from Airtable. Using the ‘Send email’ action and set that up accordingly.
Hope this helps. Best of luck.