Dear list!

I want to try out gnus for reading email. Currently, I use mutt with IMAP over ssh like this:

set tunnel="ssh -q code.cjb.net 'export MAIL=maildir:$HOME/Maildir; /usr/lib/dovecot/imap --exec-mail imap'"

After reading the documentation of gnus, I tried the following:

(setq gnus-select-method '(nntp "textnews.news.cambrium.nl"))
(setq gnus-secondary-select-methods
 	'(
		(nnimap "code.cjb.net"
        	        (nnimap-stream shell)
		 	(imap-shell-program "ssh -q code.cjb.net 'export MAIL=maildir:$HOME/Maildir; /usr/lib/dovecot/imap --exec-mail imap'")
		 )
                (nnimap "test"
                     (nnimap-address "localhost")
                     (nnimap-server-port 1234)
		 )
	)
)

While the second entry "test", works it requires:

 a. a working ssh-tunnel before I start gnus
 b. that the imap server is configured to listen on a port and to authenticate
 c. that gnus manages (asks me about) username and password for the imap server

All of which are unnecessary in my current setup (the mutt-onliner above).

Why does not the first entry above "code.cjb.net" work? (gnus says:
     {nnimap:test} (opened)
     {nnimap:code.cjb.net} (denied))