How to set up a second server to send on the same domain?

Question

Mail server

There is a domain with mail on protonmail for sending and receiving letters (spf mx, etc. are registered)
You need to configure a second server for sending, since protonmail limits the number of sent letters, the helmet is 50-60 letters per day.
What services to use? Would namecheap work for this?

Answer 1

https://aws.amazon.com/ru/ses/