How to delete xxx.xxx emails from the server?

I use horde email software but I have more than 100.000 emails in one account and i want to delete them at once and not 500 at a time?

Does anybody can please help me out how I can do that since I have root access to the server.

 

I also figured out that my webserver is sending out emails from my domain to my emails. That's how the server is spammed by my server. It's a real pain in the ass! How can i get rid of this? Please help!

 

enable your spamassasin function

 

Thanks MeetHere. I enable it.

I still don't know how to delete the spam emails on the server.