Once you've tried out the sample schema files on the sample text included, you can get daring and try importing some text of your own into a Texis table with Timport. The following schema file matches mbox formats created with many standard Unix mail programs.
#
# import a mailbox into Texis
#
database /tmp/testdb
table mail
# take multiple records from a single file
multiple
datefmt x, dd mmm yyyy HH:MM:SS
# name type tag default_val
field From varchar />>^\RFrom\x20\P=[^\space]+ UNKNOWN
field Subject varchar Subject UNKNOWN
field Date date Date
field Text varchar -
# create table mail(id counter,From varchar(80),
# Subject varchar(80), Date date,Text varchar(5000));
You should be able to create a table with the create table command listed above, then run a command something like this:
timport -s mbox.sch -v -t mbox
After a successful importation you'll be able to do concept queries on the text field of the message and locate all that important traffic you could never find again.