Question

A records, mx records sbs 2003 exchange

DNS, SBS, Exchange, SBS 2003, Exchange 2003

I was just wondering if these are correct.
mail.its-aust.net. 1741 IN A 144.131.55.95
its-aust.net. 1741 IN MX 10 mail.its-aust.net.
if 144.131.55.95 is my static ip and I point the relevant ports to the ip of the server will the mail get to the sbs exchange server

This is a standard configuration. An A record is created. The MX record points to a valid A record with an appropriate weight factor (10 in this case). As you suggest, the next step would be opening the appropriate firewall ports to permit message flow to/from your mail server.