mairix-saved-searches

mairix-saved-searches is a variable defined in `mairix.el'.
Its value is

nil

Documentation:
Saved mairix searches.
The entries are: Name of the search, Mairix query string, Name of
the file (nil: use `mairix-search-file' as default), Search whole
threads (nil or t). Note that the file will be prefixed by
`mairix-file-path'.

You can customize this variable.