Newbie question: Tiger server to Leopard, but with a hardware migration in the mix

Hello, I have an older Tiger server, mostly for light web and mail service. It's time to retire the old hardware, since it won't be supported under Leopard server, and I'm beginning to plan the migration. After reviewing the documentation, it appears that the Standard server would be the best fit, especially since it would allow me to backup via Time Machine. I have two gotchas that I have run into -- and I could use some good advice on how to best handle: 1) Mail migration: it appears even under a migrate install that OS X Server Leopard requires setup in "Advanced" mode. This is problematic, since I really don't want the complexity of advanced, I just want to move my mail DB over so my users don't lose e-mail. Is there a way to do this without dealing with "Advanced" mode? 2) Firewall: I do have the IP firewall configured and running in OS X Server Tiger. I do this principally to keep SSH dictionary attacks out (even though I don't use the service) -- is there a way to deal with this in "Standard" mode? If I read the documentation right, the firewall in OS X Server Leopard only works in "Advanced" mode? Many thanks for your help on this. - Matt