Is there a method of accessing an Exchange server that does not have IMAP or POP3 enabled without Outlook? It does not appear that Outlook Express supports Exchange (only IMAP and POP3).
You can use Thunderbird to access Exchange e-mail and contact lists.
Edit - Oops, this uses IMAP, didn't answer the question.
I know thunderbird and eudora have support for SimpleMAPI so they can talk to an exchange server but the command set of what they can do is rather basic (you need Extended MAPI support for the whole set)
afaik Outlook is the only windows client with full support for Extended MAPI.
The only way I can think of is if the Exchange server has Outlook Web Access (OWA) turned on. You can test this by trying the server name in your browser like so: http://server/exchange.
If you mean programmatically then the recommended way is to use WebDAV (which is what OWA uses).
@Jon I think the method you linked to uses IMAP.
Edit: @Pat: SimpleMAPI is the protocol that allows applications such as Word etc to talk to your email client, not your email client to the server - ExtendedMAPI is needed for that, which Thunderbird doesn't support.
There's also Exchange Web Services in newer versions of Exchange.
If you need to use Outlook Express and talk to an Exchange server which doesn't support IMAP/POP3, you're stuck, sadly.
The Outlook Web Access URL is more likely http(s)://server/owa
Exchange 2007 is SSL only by default.
If you're willing to consider a major change, you could look at Snow Leopard's support of Exchange through iCal and Mail programs. I find it isn't as robust as outlook (expected), but it gives me better off-site performance as the RPC protocol isn't active through TCP/IP connections on our server. I find that the RPC via VPN or HTTPs to both be immensely slow. Mac Exchange to the rescue, unless I'm on my windows box, then it's Outlook Web Access (aka "owa" aka webmail).