Does anyone know slingshots alternative port settings for secure smtp access outside their network?

Had a customer, of a customer, call today wanting to send email via a telecom dsl connection using their @slingshot.co.nz home email account.

All I found on the slingshot website was http://help.slingshot.co.nz/app/answers/detail/a_id/474/kw/ssl
It doesnt specify the alternate port number (other than 25) and we tried using the hint of 465 but couldnt connect to the server.

It appears the article may be trying to tell people to use smtp.slingshot.co.nz +outgoing auth +SSl on 465
But there isnt anything listening on 465.

In the end i told the customer just to use smtp.xtra.co.nz and change it back when they got home. Rather annoying for the guy as he travels alot.