mailbox full bounce to sender due to forwarder

[jganders]

I have 2 accounts: 'jim' and 'backup'.
Using cpanel Email forwarders I setup forwarding for all email sent to jim@x.com to also be sent to backup@x.com.

Sender 'joe' is not aware that his email is also going to backup@x.com.

backup@x.com mailbox FILLS UP and will not take any more email. Now 'joe' is getting "mailbox full" bounces that says backup@x.com mailbox is full. Not good. Joe is confused.

Is there a way to prevent the sender from getting bounces from 'silent' forwarded recipients like this. I'm running linux, Cpanel.

Thanx,
Jim

[Spiral]

Yeah, don't set a mailbox limit on your backup mailbox!

Wouldn't hurt to throw in a cronjob to clear mail files older than 'X' days
so you don't have to worry about the backup box growing out of control.

[jganders]

just to make this simple, can I filter exim-generated outgoing emails? I only want senders to get 'mailbox full' emails if the mailbox in question belongs to an account on their TO:, CC:, or BCC: list.