http://www.asx.com.au/professionals/faqs-about-listing.htm
Not that expensive to list. You do have to have $xxx profit over the past xx years etc but.
With regards to SecureMail / Datamotion US etc, Datamotion Asia Pacific has the distribution rights to SecureMail.
Additionally, Datamotion Asia Pacific owns a world class datacentre in WA, as well as other security and consulting businesses / services / products.