Are emails sent when a Maintenance Request is submitted or updated?

Yes, emails are sent for Open, Update, and Close updates to a Maintenance Request record.
 
When a Maintenance Request is opened an email is sent to the tenant along with the property manager being copied on the email.
 
If the tenant updates or closes a Maintenance Request just the property manager or landlord will receive an email notifying them of the action.  If the property manager or landlord updates or closes a Maintenance request just the tenant will receive an email notifying them of the action.  For updates and close updates the other party receives an email as we don't send an email to the party making the update.