A mailbox with the ability to automatically read incoming messages?

Question

Email

Hello, the task is this:
- We need a mail service with the ability to receive and store letters.
- The service should allow reading incoming emails using an API (eg Rest). Sending letters is not required.
- I don't need a separate domain for this and wouldn't want to set up a mail server myself.
- There can be relatively many mailboxes, about 20.
- I'm not satisfied with the conditions of Google apps, Outlook office and other similar ones, they still have a little for other services, and for 20 users a rather large amount comes out per month.
Perhaps I'm posing the question incorrectly and generally digging in the wrong direction. Correct if anyone has come across.

Answer 1

Make 20 boxes on any free server. Why is POP3/SMTP/IMAP not an API for you?