Can Mail modules provides simple load-balancing (round-robin and client IP) across backend servers?

Server NGINX
1

Can Mail modules provides simple load-balancing (round-robin and
client IP) across backend servers Like http HttpUpstreamModule?

upstream backend {
ip_hash;
server backend1.example.com;
server backend2.example.com;
server backend3.example.com down;
server backend4.example.com;
}

mail

{
…
proxy_pass backend;
…
}