Exchange 2013 outbound mail setup?

Question

Microsoft Exchange

Good afternoon, help in setting up outgoing emails. There is a mail.test.ru domain inside which there are employee boxes (mail exchange took place directly from 1 employee with the box name: [email protected] to 2 employee with the box name: [email protected] 2 employees have an address from whom: [email protected]). There is also a corporate mailbox [email protected] for all employees (he is 6-7 years old), you need to receive and send mail from other mail domains through this mail and that the sender's address contains: [email protected] (for example : 1 employee sends mail to [email protected], the recipient in the sender's address displays: [email protected] Tell me where to dig or what rules to create?Thanks
PS AD has not been raised yet (all employees will go to their mailboxes via the Internet)

Answer 1

The lack of answers indicates that the question is not clear to people. How can there be "outgoing" and "inside the organization", and then also sent through one box.
So you do not be offended, but the question itself resembles the question "how to assemble a cat from shawarma."
Write what you want, maybe someone will help.