Setting up email to automatically apply after an opportunity stage is set to closed.
We use opportunities to determine jobs closing when a job is complete. When that happens I want to send emails to the customer at regular intervals of 1 week, 1, 3, 6 months, and 1 and 2 year intervals. I have the email templates prepared but I cannot figure out how to set the auto trigger when an Opportunity stage is set to closed to put the customers emails into motion. I figure it will take 1 workflow rule for each email but when I select the job to check for stage being modified it will nto let me change the email to a contacts template and the Opportunities templates do not allow me to address a contact.
FYI we do not use accounts as our business is mostly residential