How to choose a payment acceptance service with automatic sending of information products?

Question

Automation

We need a fully automated system for accepting payments and sending the information product (archived file) to the buyer.
Selection criteria:
- reliability of the system
- good usability
- low commission from transactions
Please advise, knowledgeable people.
If you have experience using it, please share your thoughts.
Thank you all for the replies.

Answer 1

As an option Yandex.Money.

Answer 2

unitpay.com

Answer 3

www.avangate.com but usability is not very good in my opinion