You'd have to check the iprimus site, bigpond is mail.bigpond.com for both in and out but I don't know about iprimus, if you've had no luck when I check back later I'll jump on the iprimus site to see what I can find for you.
EDIT:
POP (receive) Server: pop.iprimus.com.au
SMTP (send) Server: smtp.iprimus.com.au
That wasn't hard,
link to iPrimus mail setup