repeated email viruses

I have norton anti virus 2003 which was updated from 2002.I seem to keep getting bogus email that norton has been quarinteened .I get undeliverable mail return from maildomain.I think Norton is getting the mail with the virusesin it.But it seems to be only affecting only one of my accounts.Its like its telling me my mail was undeliverable but im not sending out any mail.Also it seems to happen when I get mail from one person on my email addresses.Also after I delete the quarinteened mail I run a anti virus scan on my computer and there is no found viruses.Like i said it seems to be only hetting one of my email accounts.