Add an additional email address to account?

Is there any way to add a second email address to our account? What’s happening is that if I’m having a conversation in the Forum, the notifications of follow-up replies go to a co-worker’s email. In order for me to know that there’s a response, he has to forward the notifications to me. We don’t want to take him off the account (not the least because he set it up), but we’d sure like to have a second email address active.