Re: [exim] remote_max_parallel by domain?

Quoting Marten Lehmann:

> we have used remote_max_parallel = 20 for a long time and it worked
> fine. But currently we cannot deliver emails to a big German ISP
> (t-online), because their mailservers respond with
>
> 421 IP:x.x.x.x - Maximum parallel connections for your IP-Address reached
>
> It seems, that are allowed to use only one connection at a time. Thats

It seems to me that there are two parallel connections allowed. Not much
for a busy mail server, but you could try to contact their postmasters
and get them to raise the limit.

remote_max_parallel is probably not what you think it is. It controls
the maximum number of connections a single message initiates, nothing
more, as there is no central queue manager in Exim. If you are using
queue_only, it controls the maximum number of connections a single queue
runner will start. This is all written down in detail in the spec.
The spec also tells you to use queue_smtp_domains (and run a queue
runner fairly often) if you want multiple messages to be delivered in a
single connection.