How to teach postfix to send mail using multiple ip?

Question

postfix

Very often, one of the clients on the server sends thousands of letters, when most of them are on the same domain, you often receive a thrashing of too many letters, well, a link to the description of what to try in an hour or send more slowly.
Of course, you can set up sending once a second, but it will not be ice. Someone sent a lot of letters, but everyone will have to wait.
There are 8 ips on the server, I would like postfix to send everything through different ips with a large number of letters.
I don't find it in the standard documentation.

Answer 1

smtp_bind_address = 10.12.15.6
/etc/init.d/postfix restart

Answer 2

Postfix can bounce such emails...
According to my observations, if you use SPF+DKIM, then most public mail servers remove the limit on the number of emails from one domain/IP.