First: create a backup of your mail folders (see nnmairix caveats).
Setting up mairix is easy: simply create a .mairixrc file with (at least) the following entries:
# Your Maildir/MH base folder
base=~/Maildir
This is the base folder for your mails. All the following
directories are relative to this base folder. If you want to use
nnmairix with nnimap, this base
directory has to point to the mail directory where the
IMAP server stores the mail folders!
maildir= ... your maildir folders which should be indexed ...
mh= ... your nnml/mh folders which should be indexed ...
mbox = ... your mbox files which should be indexed ...
This specifies all your mail folders and mbox files (relative
to the base directory!) you want to index with mairix. Note that
the nnml back end saves mails in MH format, so you
have to put those directories in the mh line. See
the example at the end of this section and mairixrc's man-page
for further details.
omit=zz_mairix-*
This should make
sure that you don't accidentally index the mairix search results.
You can change the prefix of these folders with the variable
nnmairix-group-prefix.
mformat= ... 'maildir' or 'mh' ...
database= ... location of database file ...
The format setting specifies the output format
for the mairix search folder. Set this to mh if you
want to access search results with nnml. Otherwise
choose maildir.
To summarize, here is my shortened .mairixrc file as an example:
base=~/Maildir
maildir=.personal:.work:.logcheck:.sent
mh=../Mail/nnml/*...
mbox=../mboxmail/mailarchive_year*
mformat=maildir
omit=zz_mairix-*
database=~/.mairixdatabase
In this case, the base directory is ~/Maildir, where all my Maildir folders are
stored. As you can see, the folders are separated by colons. If
you wonder why every folder begins with a dot: this is because I
use Dovecot as IMAP server, which again uses
Maildir++ folders. For testing nnmairix, I also have
some nnml mail, which is saved in ~/Mail/nnml. Since this has to be specified
relative to the base directory, the
../Mail notation is needed. Note that the line ends
in *..., which means to recursively scan all files
under this directory. Without the three dots, the wildcard
* will not work recursively. I also have some old
mbox files with archived mail lying around in ~/mboxmail. The other lines should be
obvious.
See the man page for mairixrc for details and
further options, especially regarding wildcard usage, which may
be a little different than you are used to.
Now simply call mairix to create the index for
the first time. Note that this may take a few minutes, but every
following index will do the updates incrementally and hence is
very fast.