Pulling email in-house with Exchange 5.5 /dsl

[CPUJockey]

I am wanting to pull our e-mail in-house using:

* Exchange 5.5 on NT4 server
* SBC Business DSL connection with static IP for the server.
* Cisco router/firewall/vpn
* 60 users, ~15 at vpn locations
* no "outside" e-mail checking needed

Previous experience:
* 2 years with 5.5 on NT4
* T1 connection to AT&T
* Same series of Cisco routers

Besides making sure that relaying is off, are there any major specifics that I need to consider related to the above combination?

Thanks in advance.