As you can see, webmail was recently upgraded as part of a system upgrade. I'll make notes here with useful hints. Let me know if there are any questions.
Go to Settings, Mail, Accounts, Add Account. Choose Other and Add Mail Account.
Fill in your details. Choose IMAP (should be default). As incoming and and outgoing server, use mail.fupp.net and your username and password. You must enter both username and password both places. Click Next, check that Mail is enabled and Save.