nnimap - authentication

[Harry Putnam <reader@newsguy.com>]

Haven't been able to figure out how to get a better setup for
authentication on an imap server.  After looking through that section
of the nnimap info, I guess I need the `login' option.

The author of nnimap info came perilously close to breaking a long
standing unix tradition of not giving a usable example on pain of
death.

The author comes very close to supplying a usable example, but must
have begun to feel the weight of tradition, and resolve strengthened
we get comments that can only be understood by lisp programmers. And
no real usable example:

     Please note that the value of `nnimap-authenticator' is a symbol!

It must be pretty exciting news to require an exclamation point.
Too bad us non-programmer types, get nothing from that... except, "OK
so what is a `symbol!'?"

Does it mean I need something like this?

          (nnimap "mail.server.com"
                  (nnimap-authenticator anonymous)) 

Putting the `login' part in place of anonymous?

       * "login:" Plain-text username/password via LOGIN.

But then what about the `username' `password' part? Where does it go.?