Nope. That's an issue between the team member's ISP and the customer. This is how I see it:
@aol.com sends mail to @dreamhosters.com, which then forwards to @hotmail.com and @yahoo.com
The @yahoo address is borked, so Yahoo will send the error message directly to @aol, completely bypassing @dreamhosters.com
The only way to avoid this is a) write your own fancy mail handling system (not recommended) or b) stay on top of your team's mailboxes (the right way to handle this). Really, is it that hard for someone to maintain a mailbox? Especially if it's used for business.