Possible to include addressee in headers?

Hello, I'm using smartlist for a newsletter with about 4.500 subscribers. Every time I send my newsletter I get some mail delivery failures returned, mostly because of terminated accounts. Most failure messages provide a clear error message that includes the incorrect e-mail address. Unfortunately, some mail servers return an error message with the original e-mail (send by smartlist) attached, but with no mention of the e-mail address that failed. Is there a way to have smartlist/sendmail include the addressee in the headers when it sends the mail? In that way I would be able to find the incorrect address in the header of the message that is returned to me. -- Thanks in advance, René Pijlman <R.Pijlman@applinet.nl>