No local mail from "mail"

I'm using Postfix on the server for the MTA. (An interesting side note, when I send local mail to a user via "mail <username> <text> <CTRL-D> That user never gets it. (Though it is in their /var/spool/mail/<username>, I can see it with root as vi there. When that user types "mail" it responds that there are no new messages. Any Ideas? Thanks, -Mettius --