Electronic Document Service Needed - California US Resident Preferred

I need an electronic service to manage the emailing of documents. The service should include:

- Email Proof of Service: Sending documents via email.
- Proof of Delivery: Ensuring documents are delivered.
- Delivery Confirmation Email: Providing an email as proof of delivery.

Ideal skills and experience:
- Experience with electronic document services
- Reliable and timely email handling
- Ability to generate and manage delivery confirmation emails