If you're creating IDs, then there's no way. If you only had one ID but 5 different e-mails accounts... by default you'll receive all the e-mail in your inbox (unless you're connecting to those e-mail accounts using IMAP, of course. I'm assuming that you're using POP)
Before asking, do a search... if you don't find the answer, then ask The purpose of this forum is to help others in the community, that's why it's called Sitepoint and not Linkpoint. SP Guidelines - No fluff.