What about creating a "dar2" user (with admin privileges), then moving the dar2 crontab entry to that user (then you could set a custom mailto value for the crontab belonging to dar2)?
Or, install the
Mailsorting contrib and create rules to forward the dar2 notifications to another mailbox.
Or, setup an account for 'root' in Thunderbird and create a filter to forward the dar2 messages.