Você deve definir sua configuração dentro de /etc/logwatch/conf/logwatch.conf
.
Isso substitui os /usr/share/logwatch/dist.conf/logwatch.conf
e /usr/share/logwatch/default.conf/logwatch.conf
.
De link
However, Logwatch, starting with version 7.0, implements a mechanism
to allow modifying the local system easier. These modifications may
be needed either because the configuration of the service that writes
to the system log has been altered from its default, or because the
Logwatch user prefers what is reported or how it is reported by
Logwatch to be different.
You can customize the output of logwatch by modifying variables in the
/etc/logwatch/conf directory.
Default values are specified in the /usr/share/logwatch/default.conf
directory. Your distribution may have set additional defaults in the
/usr/share/logwatch/dist.conf directory. All the variables available
are declared in the files under these directories. You can change the
default values to modify how or what is displayed with logwatch.