`smtp-server' not defined

[evan]

Hi all,

Any idea why I get the message "`smtp-server' not defined" when I try
to send mail via gnus? I have tried to see what is wrong but I cannot
find anything.

Thanks.

I have the following configuration (this is the same configuration
proposed in emacs-wiki):

(setq gnus-select-method '(nnimap "gmail"
                                  (nnimap-address "imap.gmail.com")
                                  (nnimap-server-port 993)
                                  (nnimap-stream ssl)))
(setq message-send-mail-function 'smtpmail-send-it
      smtpmail-starttls-credentials '(("smtp.gmail.com" 587 nil nil))
      smtpmail-auth-credentials '(("smtp.gmail.com" 587 nil nil))
      smtpmail-default-smtp-server "smtp.gmail.com"
      smtpmail-smtp-server "smtp.gmail.com"
      smtpmail-smtp-service 587)
(require 'smtpmail)