What ports need to be opened and forwarded to an Exchange server for it
to send & receive email and serve Outlook 2003 clients outside the
firewall? I'm using a Netgear DSL router and a SBS 2003 server.

you can find a list of this ports there :
http://www.microsoft.com/technet/prodtechnol/exchange/guides/E2k3SecHardGuide/bfa2eb1a-66f0-4427-b8b7-34d7f175bfab.mspx

hope this helps ;)

jul.

Ports to open for SSL based IMAP and POP communications are
respectively 993 and 995.
You may also open HTTP-Secure (HTTPS) Port 443 which Outlook Web Access use.

Kind regards.

Well for this one would generally use a VPN, outlook web access, or
Remote web workplace, if each user has a dedicated pc that lives at
the office one can use RWW, if one just needs to get access to mailbox
the browser based OWA works really well, if one needs outlook to sync
one would hookup a PPTP VPN all of which are common combo's for SBS,
shall I clarify the options for one of these?

Ok, found the cheat sheet list of ports

http://www.windowsitpro.com/Files/40832/Table_01.html

But again, will suggest that you may find OWA way simpler then setting up a VPN