An odd problem, and solution?

one line summary: Trying to streamline access via dns and possibly some scripting, or . Internal mailserver on a static local address (more info about this setup and why a couple paragraphs down!) For desktop Macs, I can put in the local ip or private hostname and all works fine, obviously the latter gives me more flexibility, but that's aside from the main point. For laptop users, a local hostname will not resolve publicly, and although the public hostname resolves correctly (privately or publicly) via a dynamic dns service, I believe the connection is denied at the router since it looks like a spoofed packet. Unless the machine is truly outside the network, then it works. So far this is a routing and not a dns issue strictly, though I'm wondering/hoping for some fancy dns work to make this happen. This is a small operation, really only 6-7 users and a couple with laptops. I'd like the laptop users to have the easiest experience possible. I'm afraid the only answer might be "do it the [b]right[/b] way, buddy." I have a similar setup at home; I want the flexibility of my own server and with IMAP capabilities mixed in (plus unlimited space, yay!) but I don't need and in fact via my cable modem agreement am restricted from running a full-fledged public email server (nevermind mx record "blah" in case my IP changes). This one downloads via pop3 and sorts into mailboxes from there. i.e. full network availability of a high-traffic server without the cost of co-hosting or paying per month for services. Personally I think that's a pretty nifty setup for the right kinda business and situation. The one big flaw is access. Two workarounds: - Use network locations for "local" and "outside," the local one pointing to a dns server resolving custom.dyndns.org to the private local address, and the "outside" location using a dns server with the public ip (and port mapping, easily done). The mail client won't know the difference. But this is a manual change. I'm fine with this but I'd like to make it as transparent as possible! - Setup two email accounts for every mailbox they have, one with the local and one with the public address. A bit clunky but technically it works. Not a huge fan of this. After a bit o' searching I found a batch file which pings a local address and if it's up, modifies windows' system32/drivers/etc/hosts file to resolve custom.dyndns.org to the private local address, and if there is no (quick?) response it changes the hosts file to reflect the public IP resolution. Buuut that's a batch file and does me no good on tiger. And I'm no programmer. [i]Is there another way to do this? Can anyone verify this would be possible?[/i] If I need to write some code I have a friend who might be able to (I've worked with him on projects in the past). Thanks all!