SMTP/POP performance benchmarking

[reach_prashant]

  hello friends 


   i have installed qmail (SMTP/POP) and courier (IMAP)  on 8 nodes running
IBM AIX 4.3.3  , and is  running fine on all the AIX 4.3.3 nodes, but
before we use it as in practical environment i need to load test just to
check how much load it can sustain , 

   if anyone knows any utility/tools which are available free of cost ,then
please point me to those tools 

regards,
Prashant Desai