[Mailman-Users] howto make 'notmetoo' default?

[Tom Boeken]

Hi,

I would like to make one or more options in the Membership Management 
for all available lists default when adding a new member, e.g. set 
'notmetoo' or 'ack'.

Is there a way of doing this through crontab, say check this setting 
once a day and change it through some shell-script?

Thanks in advance.

Tom