Create the email template
Click Setup, then Content.
Click Emails, then Configuration.
Click Triggers, then Add Email.
Create the email template as needed, using the replacement fields in the column on the right.
Click Save.
Set up the notification
Click Setup, then Settings.
Click Notifications, then Add Notification.
Enter a title in the Description field.
Select Date from the Type dropdown.
Select Employee (Employee) from the Table dropdown.
Select StartDate from the Field dropdown.
Click Add Email.
Select the template you've created from the Email Template dropdown.
Select when to send the email, for example: '5 years after' will send the email 5 years after the employee's start date.
Select the recipient:
Employee: The employee themselves will receive the email.
Reports to: The employee's line manager will receive the email.
Other: Select this option and then add an email address to send this email to a specific recipient.
Click Save.