Ah, I see. When you say '"when it sends the email", do you know what mechanism "it" is using? if 'it' is a plugin then the plugin can be tweaked to execute in the context of the calling user. If 'it' is a workflow and isn't triggered on-demand, then it will run with the privileges of the owning user. This can be changed by assigning the workflow to a user in the same business unit / with more suitably restricted permissions.
Initially, I'd ask your Click Dimensions partner/contact for help with this.
Rob