In all cases, your full email address should be used for login.

You should first make absolutely certain that the NNTPSERVER environment variable is not defined. To do so, run the following command:
echo $NNTPSERVER

If something other than a blank line is printed, check your initilization files (probably .profile) for commands referencing NNTPSERVER. Comment out any such lines, and log out and back in.

trn
Using a text editor, create a file in your .trn directory called "access". The access file should be formatted like this:
[default]
NNTP Server = news.foxvalley.net
Auth User = your_email_address
Auth Password = your_password

tin
Tin will automatically ask you for a username and password. Be sure to use your full email address for your username. If you wish to have your username and password sent automatically, create a .newsauth file in your home directory using a text editor. The file should be formatted like this:
news.foxvalley.net your_password your_email_address

slrn
Using a text editor, create a file in your home directory named ".slrnrc". It should be formatted like this
nnrpaccess "news" "your_email_address" "your_password"

pine
In the pine configuration, set your nntp-server to look like this:
news.foxvalley.net/user=your_email_address
The news-collection must also be set to something like this:
news-collections="FVI Newsgroups" {news.foxvalley.net/nntp/user=your_email_address}#news.[]

You'll be prompted for a password. If you want pine to save your password, you must have the .pine.pwd
file in your home directory. To create it, run:
cd
touch .pine.pwd

Once this file is created, re-run pine. After typing your password in pine, it will ask you if you wish to save your password to disk.