[Mailman-Users] slow delivery times

Using Mailman version: 2.1.3
Solaris 9

Hi

I am having a problem of delayed or slow delivery of emails of a list
with around 1600 subscribers. Below is an Exim log for a small
testlist. Where does the <= testlist-bounces at mailman.sghms.ac.uk come
from? I assume mailman sends this - what is it for? can it be turned
off? could it slow the list processing down and so the delivery of emails?

Any other ideas as to why the mailman is sending out emails slowly over
a long period of time and how delivery can be speeded up?

Thanks

Paul

2005-05-04 10:26:02 1DTG8o-00042m-3C <= pkey at sgul.ac.uk
H=(mailhub2.sghms.ac.uk) [194.82.51.8] P=esmtp S09
idB7895EC.6060204 at sghms.ac.uk
2005-05-04 10:26:02 1DTG8o-00042m-3C => testlist
<testlist at mailman.sgul.ac.uk> R=mailman_router T=mailman_transport
2005-05-04 10:26:02 1DTG8o-00042m-3C Completed
2005-05-04 10:26:03 1DTG8p-00042r-Qf <testlist-bounces at mailman.sghms.ac.uk H=localhost.sghms.ac.uk
(mailman.sghms.ac.uk) [127.0.0.1] P=esmtp S$15
id=mailman.66.1115198763.4769.testlist at mailman.sghms.ac.uk
2005-05-04 10:26:08 1DTG8p-00042r-Qf => pkey at sgul.ac.uk R=sghms_smtp
T=remote_smtp H=imail.sghms.ac.uk [194.82.51.24]
2005-05-04 10:26:08 1DTG8p-00042r-Qf Completed