[Exim] Performance issues

Hi!

I am running exim 3.36 on a single P4 1.6GHz RedHat 7.3 machine with 768mb of RAM. A single Perl programme is generating email. It seems that we have a capacity limit on that machine of 12,250 deliveries per hour.

Setup is pretty much default, i.e. we are not using split spool directories.

Can anybody give me ideas on how to get this figure up? I would dearly love to get to 50,000 per hour per server. I have a sustained requirement for 1-2 million emails per server per day. This is not a spamming application - but a very large system of double opt-in lists with a VERY low rate of complaints or problems.

Any clues appreciated.

John
Toronto, Canada