Watch out for the ‘River Troll’ February 11th, 2020 2003-05-30T10:23:15+12:00 The NZRCA is experimenting with Tagged Message Delivery Agent (TMDA) to protect the various generic *@whitewater.mytestsite.nz email addresses from spam. If you send an email to these addresses, you may be challenged by the ‘River Troll’. Simply follow the instructions in the email to ensure your message gets through. Once you have been accepted as a sender, you won’t have to repeat the process. This technique is particularly effective against spam from non-existent accounts.