[exim] How to configure exim to run a command on SMTP error …

My application sends emails via exim to members of my site. Occasionally
people move from an organisation and don't update their email address. I
need to somehow run a command if I get one of these 'bounces' to update
the status of the user in the application.

Can anyone point me in the right direction?

Clive Haworth
www.amiplaying.com