Can’t get to email server in WinME

There is one computer on our network that cannot access email via the usual ‘mail.blahblah.com’ settings in Outlook (or OE for that matter). We can access using the direct IP address, however. The weirder part is that we can access any and all web pages via URL. I have double-checked the DNS entries, and they are correct–as I said, I can access web pages without a problem. All other PCs on the network access their email via the mail.blahblah.com address. Any ideas?