[nzlug] Exim: Limiting outgoing connections on Debian

[Daniel Lawson]

> Anybody know how to limit Exim4 to one connection to my smarthost at a time?
>   

According to the very excellent Exim 4 book, which is written for Exim 4
but should still apply to whatever Debian has, you could try

serialize_hosts = your.upstream.mta

This will cause exim to check to see if it already has a connection open
to a host it is attempting to deliver to, and if so wait and reuse that
connection instead.