How to make an auto-responder for emails inside messages?

Question

Email

There is a problem with the avito service.
A potential client can send his e-mail through the avito service to the employer.
The employer receives a message FROM avito and inside the message is already the client's email, i.e. if an autoresponder is connected, then the answer will go to avito's email.
How to make the answer from the autoresponder go to the client? Thanks

Answer 1

Reply-To: (RFC 822, RFC 1036) The name and address to which replies to this letter should be addressed. If, for example, a letter is sent by a robot, then the address of the mailbox that is ready to receive a response to the letter will be indicated as the Reply-To