• Open System preferences (the gear icon)
• Internet accounts
• + to add another
• List of account types: icloud etc. scroll down to the bottom. Click “add other”
• Add a Mail Account
• put in your name, email address and password
• It will probably say “Account must be manually configured”: that's ok.
• click POP server. enter mail.riverland.net.au
  • Username, password, outgoing server: the usual settings

• If it's an IMAP account, then click IMAP server, servername is mail.rivwe.com
  • Username = email address, password. It seems to guess SSL and port numbers successfully.

(Mac OS X 10.10, july 2015)