How to empty mail root

Hello i need to reduces the size of the mail of root (var/mail/root),
I have mail from last year.

how can i do it?

thank you for your time.

This will delete all mail for user root:

cat /dev/null > /var/mail/root

yes , thank you for the answer but i don�t wan�t to remove all the mail i wan�t to leave last ten o 20..can be done?? thank you very much

I think you can specify a range to delete.
Like if you have 14020 mails, you could delete 14000:

mailx -N
> d  1-14000
> q

Or something like that. Do a search on the forum, there a few other threads on this already.