[exim] Smarthost + queue worker keep alive the connection

Hello,

I’m sending out millions of emails from a server on a regular basis.

The emails go to a single a smarthost that handles the delivery. I played a
lot with the configuration about how many queue workers should be running
and how many connections the smarthost should accept.

Now the only problem left is that I believe the worker processes connect to
the smarthost for every message one by one.

I didn’t find anything in the documentation (current 4.x version) that
seemed to allow me to tell the queue workers to send more than one email
through the smarthost.

This costs me a lot of time and hard cash too especially due to the SSL
overhead. Did I miss something? Is there a way to make it work?

(To make it clear, I’m talking about the queue workers on the first SMTP
server and not on the smarthost).

Thank you.

M.