[thelist] hosting and email question

[Liz]

Hi there,
I resell hosting and am having a problem with a couple of my  
accounts. I have some clients who just forward their email to aol or  
gmail or whatever and they never actually log in to the host for  
their mail and the mail ends up accumulating on the  
server. ...eventually overloading the server.


The host has a cpanel interface and it *does* have spot to set  
"Aging" But Aging is described as:
Mail aging is the process in which e-mails will be removed from the  
server automatically, upon successful log out of a pop3 session. This  
deletion will only occur if the messages are older then a specified  
amount of days.

However these clients don't log in with a pop3 so the mail does not  
get removed.

What am I missing in setting this up?  How do I set it up so that  
mail does not accumulate on the server?
thanks for your help,
Liz