smtp error

[Georg W. Otto]

Dear all,

I am trying to set up gnus to sent email from my gmx account and get an
error. Here is the setup, which I took from the emacs wiki

(setq smtpmail-default-smtp-server "smtpserver") 
(require 'smtpmail)
(setq send-mail-function 'smtpmail-send-it)
(setq message-send-mail-function 'smtpmail-send-it)
(setq user-full-name "<user>")
(setq smtpmail-local-domain "gmx.com")
(setq user-mail-address (concat "<user>@" smtpmail-local-domain))

This is the error message I receive:

Sending news via news.gmane.org using nntp...
441 You need a valid email address to post: Invalid response from SMTP
server mx00.gmx.net: 554-gmx.net (mxgmx015) Nemesis ESMTP Service not
available

Sorry, I am not very familiar with this, so I am not sure if this has to
do with my gnus setup at all.... Any idea?

Cheers,

Georg