1.6.7.1 Setting up IMAP and NNIR

If you use IMAP, then your mail is stored on the mail server and
you’ll need to use the IMAP search interface to search through
it. Download nnir.el from
http://www.emacswiki.org/cgi-bin/wiki/download/nnir.el and save it to
your ~/elisp directory. You will also need an imap.el that is newer
than the one that comes with Emacs 22. Download imap.el from
http://www.emacswiki.org/cgi-bin/wiki/download/imap.el and save it to
your ~/elisp directory as well. Because Gnus comes with an older
version of imap.el, you will need to make sure that the new version of
imap.el is loaded. Add the following to your ~/.gnus:

(add-to-list 'load-path "~/elisp")
(load-file "~/elisp/imap.el")
(require 'nnir)

Restart your Emacs. You can check if the correct version of imap.el
has been loaded by typing M-x locate-library and specifying
imap.el. If Emacs reports “~/elisp/imap.el”, then Gnus is configured
to use the updated imap.el.

1.6.7.2 Setting up POP3 and NNIR

If you use the configuration for POP3 that is suggested in this
chapter, then your mail is stored in the nnml backend, which uses one
file per message. To search this using NNIR, to install nnir.el and an
external search mail engine. The Namazu search engine runs on Linux,
UNIX, and Microsoft Windows, so that’s what we’ll talk about here. To
find and configure other mail search engines supported by NNIR, check
out the comments in nnir.el.

First, you’ll need to download and install Namazu. If Namazu is
available as a package for your distribution, install it that way, as
it depends on a number of other programs. An installer for Microsoft
Windows can be found at http://www.namazu.org/windows/ . If you need
to build Namazu from source, you can get the source code and instructions
from http://www.namazu.org .

After you’ve installed Namazu, create a directory for Namazu’s index
files, such as ~/.namazu-mail. Then index your mail by typing this at
the command-line:

mknmz --mailnews -O ~/.namazu-mail ~/Mail

and add the following to your ~/.gnus:

(add-to-list 'load-path "~/elisp")
(require 'nnir)
(setq nnir-search-engine 'namazu)
(setq nnir-namazu-index-directory (expand-file-name "~/.namazu-mail"))
(setq nnir-namazu-remove-prefix (expand-file-name "~/Mail"))
(setq nnir-mail-backend gnus-select-method)

1.6.7.3 Searching your mail with NNIR

From the group buffer displayed by M-x gnus, you can type G G
(gnus-group-make-nnir-group) to search your mail for a keyword.

If you’re using the Namazu search engine, then you can use more
sophisticated search queries such as:

Linux Emacs	messages that contain both “Linux” and “Emacs”
Linux or Emacs	messages that contain either “Linux” or “Emacs”
Emacs not Linux	messages that contain “Emacs” but not “Linux”
Emacs and (Linux or Windows)	messages that contain “Emacs” and either “Linux” or “Windows”
“apple pie”	messages that contain the phrase “apple pie”
{apple pie}	messages that contain the phrase “apple pie”
+from:example@example.com	messages with example@example.com in the From: header
+subject:”apple pie”	messages with the phrase “apple pie” in the Subject: header
+subject:apple +subject:pie	messages whose Subject: headers contain both “apple” and “pie”

If
matching messages are found, then you will see a temporary group with
the results. Although you can’t delete messages from this view,
reading and replying to these messages is the same as reading and
replying to regular messages.

To see a message in its original context, type G T
(gnus-summary-nnir-goto-thread) from the summary buffer. This opens
the message’s original group. If Gnus asks you how many articles to
load, press RET to accept the default of all the articles.