[Exim] large messages.

Hi I have the following settings in my config file.

# router
outbound_big:
self = defer
driver = lookuphost
transport = out_big
condition = ${if >{$message_size}{200K}{yes}{no}}

# transport
out_big:
driver = smtp
delay_after_cutoff = false
keepalive = true
batch_max = 1
serialize_hosts = *

Basically I wish to have large emails go out one at a time. However I am
finding that the emails go out straight away (especially if several users
decide to send large emails at the same time), clogging up one of our remote
pops ISDN Line. They are going out on the correct transport.
Any suggestions/pointers most welcome
TIA
Andrew










--
Ambition is a poor excuse for not having enough sense to be lazy.