Software

oh, sure, sbs is great as long as you don't mind a cajion services running, as long as all your vendors can use whatver version of sql server ya got...i would not buy sbs because i 'might' need the capability in the future. i would buy the packages i needed now individually. better for your career also imho.
'user error'. ouch. if that was zing, guess surprised haven't had one before now (smile). so maybe i could say he agrees separate packages more robust?? i say do lots of homework in technet and support at www.microsoft.com. read the support articles. read between the lines.
you will end up with a bunch o stuff besides sbs in future, imho. accounting database engine maybe. backup software maybe. i just wouldn't promise management i can do everything on one server. sbs is for wimps, dl

I've never tried installing SBS 2000 exchange on a seperate box that from my DC with AD. Haven't checked to see if theres anything on Microsofts site about it. I have installed SQL on a seperate box and didn't have problems so I'll assume you can do it with exchange.

I see it as the second box with exchange would be secondary DC on the network with exchange installed on that with your primary DC [holding the primary copy of AD and the Global Catalog] having DNS DHCP RRAS Terminal Services, Certificate Authority installed. humm might check that out on our test network.

wasn't a ZIG against you Sgt! it was against the supposedly IT gurus who would call me up asking for help cuz they knew I ran it. 99% of the time their problem was they didn't know Exchange or ISA server and mostly Active Directory and ended up mucking up the whole works. SBS isn't Enterprise level network software where you have a bunch of different pysically seperate sites, 100s of users in each one and clusters of servers [DCs Mail, Database]. Its for a company with 75 computers max that wishes to host their own mail service, have a database server and not a big IT department to run it all [usually just one guy]. For $1500 USD you get W2003 server, Exchange 2003 and ISA server 2000. It can run all on one box if done right, works just like an Enterprise Level network BUT can't establish trusts with other domains. Not a bad deal at all. I run the DC with Exchange and ISA on one box, a file server, a SQL server a secondary DC and a seperate public web server. Have 58 workstations and it runs like the Pink Bunny! Only problems I have if users losing files [forgetting where they put em or accidently deleting em]. And food, coffee, ketchup on the keyboards and the occasional unauthorized game software, damn screensavers, and weird wallpaper. I run Norton Corporate Antivirus 8.0 with Exchange and I really like that cuz I don't have to do anything once it's setup.

IMHO those that have called me up for help usually don't test crap out like scripts on a test network which they then stick on their production network and then find it's mucked it up. They have management that allows idiot programmers to come up with off the wall programs that don't work on a Windows Platform and try to use em [which really mucks up the network] and generally play around tweeking this or playing with that so they aren't bored.

lastly is the damn users themselves and not having sufficent security policies in place so users don't muck up their computers or the network. Bored users are bad. Whats worse is the user who play "get even" with those they don't like. As the proverb goes... "Nothing screws things up faster than people" .