[Exim] Overhead using perl for SQL authentication.

I'm currently running a NT based Imail server that uses a MSSQL user
database. I would like to convert it to linux and run exim but I need to
keep the SQL user database. I know exim can use sql via a perl integration
but I am concerned about system load. The machine is a dual 600 mhz with
512mb ram serving about 7000 users. I would appreciate any input anyone has
on the subject.

Thanks,
Garrett Richmond