On the project documentation pages (a kind of mirror of the official docs), there is a mailto link at the bottom of every page.  The address (kde-docs@kdemail.net) is not valid.
                                                                                                                                                                                                                                          
Delivered-To: greg.rundlett@beangroup.com
Received: by 10.140.188.10 with SMTP id l10cs190019rvf;
        Wed, 7 Oct 2009 12:24:42 -0700 (PDT)
Received: by 10.141.41.21 with SMTP id t21mr5848rvj.93.1254943482515;
        Wed, 07 Oct 2009 12:24:42 -0700 (PDT)
Return-Path: <>
Received: by 10.141.41.21 with SMTP id t21mr8079rvj.93;
        Wed, 07 Oct 2009 12:24:42 -0700 (PDT)
Message-ID: <000e0cd50a867d11d004755d4c4e@googlemail.com>
From: Mail Delivery Subsystem <mailer-daemon@googlemail.com>
To: greg.rundlett@beangroup.com
Subject: Delivery Status Notification (Failure)
Date: Wed, 07 Oct 2009 12:24:42 -0700 (PDT)
X-Failed-Recipients: kde-docs@kdemail.net

This is an automatically generated Delivery Status Notification

Delivery to the following recipient failed permanently:

     kde-docs@kdemail.net

Technical details of permanent failure: 
Google tried to deliver your message, but it was rejected by the recipient domain. We recommend contacting the other email provider for further information about the cause of this error. The error that the other server returned was: 550 550 5.1.1 <kde-docs@kdemail.net>: Recipient address rejected: User unknown in virtual alias table (state 14).