Say a user goes on vacation. How can i get my on receive applet to fire?

All it does is create a copy and sends to an archive email box with a bit of formativ processing.

Is this possible? how about if i could garantee another user will always have proxy to the email box while no one is actually logged into it?

how could i accomplishe this code to also run once, because there may be multiple users that have proxy to the email box.

Basicaly I want an applet that runs when an email is received and no one is logged into the email box. Is this possible?

thanks,