[exim] smarthost and multiple messages per connection

Hi All,

By default, exim establishes a separate connection to a remote smtp
server, even if this remote server is configured as exim's only smart host.

Since our smarthost does not allow more than 10 connections per minute,
it causes significant delays in mail delivery with default configuration.

We have since reconfigured our exim, which now runs with the following
options:

Listener:
/usr/sbin/exim4 -bd -odqs

Queue Runner:
/usr/sbin/exim4 -oP /var/run/exim4/eximqr.pid -qq2m

Mail now queues fine, but when queue runner starts up, it still seems to
establish individual connection per each message, despite -qq option:

2010-03-02 15:45:59 Start queue run: pid=5686 -qq

... skipping 10 successfully delivered messages ...

2010-03-02 15:46:01 1NmUHO-0001Rx-0g SMTP error from remote mail server
after initial connection: host <smarthost> [XX.XX.XX.XX]: 421 Connection
not accepted at this time

... skipping undelivered messages ...

2010-03-02 15:46:02 End queue run: pid=5686 -qq

Any idea what else can be missing in the following configuration?

# /etc/default/exim4
EX4DEF_VERSION=''

QUEUERUNNER='separate'
QUEUEINTERVAL='2m'
COMMONOPTIONS=''
QUEUERUNNEROPTIONS=''
QFLAGS='q'
SMTPLISTENEROPTIONS='-odqs'


Many thanks,
Alexander

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Alexander Ufimtsev
Web Software Developer
School of Computer Science and Informatics
University College Dublin, Belfield, D4, Ireland
T: +353 1 716 2926 F: +353 1 269 7262