If the bounce is generated by ESA, few features do support modification to SMTP response code.
Explore the mail flow policy as an e.g. and you should see that the response code fields/value can be changed (though I dont see a see a specific use case to change it). The message context can also tweaked via Bounce Profiles under Network. You need to setup a next text resource to include the required information and use it in the bounce profiles.
