I've heard of people getting VPN to work but haven't been successful myself. Have a Toshiba e740 otherwise connected successfully a Wifi router (can browse fine) but no luck with VPN. Also, the bundled VPN client on the PPC doesn't support IPsec (not my problem) although there are third party VPN clients out there.

Corporate e-mail in general is difficult to get remotely on a PPC. First, Pocket Outlook can only connect to a special mobile exchange server that your IT dept would have to install. If they don't want to do that, you'd be stuck with POP3 or IMAP access. Many companies only allow such access when you're connected to the network. Also, Outlook Web Access (OWA) is difficult to use. Pocket IE doesn't support OWA (b/c of Java issues or something). Doesn't seem like third party browsers do yet, although that may change. There are third party OWA server side solutions, but again you'd need your IT dept to support this. Some of this may be resolved with Exchange 2000, which my company is not using yet.