Remove references to domain that no longer exists

* doc/misc/gnus-faq.texi (FAQ 7-1):
* doc/misc/gnus.texi (Maildir):
* lisp/gnus/nnmaildir.el: qmail.org no longer exists.

doc/misc/gnus-faq.texi

@@ -1952,10 +1952,8 @@ and @uref{http://pyropus.ca/software/getmail/, getmail}.
 You should tell those to write the mail to your disk and
 Gnus to read it from there. Last but not least the mail
 sending part: This can be done with every MTA like
-@uref{http://www.sendmail.org/, sendmail},
-@uref{http://www.qmail.org/, postfix},
-@uref{http://www.exim.org/, exim} or
-@uref{http://www.qmail.org/, qmail}.
+@uref{http://www.sendmail.org/, sendmail} or
+@uref{http://www.exim.org/, exim}.
 
 On windows boxes I'd vote for
 @uref{http://www.tglsoft.de/, Hamster},

doc/misc/gnus.texi

@@ -16416,8 +16416,7 @@ have to set this variable to @code{t}.  The default is @code{nil}.
 
 @code{nnmaildir} stores mail in the maildir format, with each maildir
 corresponding to a group in Gnus.  This format is documented here:
-@uref{http://cr.yp.to/proto/maildir.html} and here:
-@uref{http://www.qmail.org/man/man5/maildir.html}.  @code{nnmaildir}
+@uref{http://cr.yp.to/proto/maildir.html}.  @code{nnmaildir}
 also stores extra information in the @file{.nnmaildir/} directory
 within a maildir.
 

lisp/gnus/nnmaildir.el

@@ -21,10 +21,9 @@
 
 ;;; Commentary:
 
-;; Maildir format is documented at <URL:http://cr.yp.to/proto/maildir.html>
-;; and in the maildir(5) man page from qmail (available at
-;; <URL:http://www.qmail.org/man/man5/maildir.html>).  nnmaildir also stores
-;; extra information in the .nnmaildir/ directory within a maildir.
+;; Maildir format is documented at <URL:http://cr.yp.to/proto/maildir.html>.
+;; nnmaildir also stores extra information in the .nnmaildir/ directory
+;; within a maildir.
 ;;
 ;; Some goals of nnmaildir:
 ;; * Everything Just Works, and correctly.  E.g., NOV data is automatically