How to set up relayhost for one outgoing address?

Question

postfix

Hello.
In general, a lot of different mail can go through postfix. It is necessary to send mail to an external mailer at a certain address ([email protected]) without affecting other addresses (*@example.ru), they are sent directly. There is a relayhost setting, but it redirects all mail.
What are the options?

Answer 1

Postfix has such a sender_dependent_relayhost_maps setting,
you can set it like this: [email protected] [gate.example.ru]
And it is this letter that will be sent to the external MTA

Answer 2

Make an alias for this address