Using exim queue_only option for large mailing lists

Hi,

We are a huge educational portal with daily newsletters to over 100,000 registered students.

We throttle newsletters but scripts that communicate with exim seem to be slowed especially when traffic levels are high. Probably the script is waiting for exim to send a given batch and reply.

Will changing exim to operate in queue_only mode and then throttling it to offload queues for every 5 minute help ?

Thanks,
Kamalkk