> Can I set up a virtual domain through one user account so
> that I don't have
> to create real users?
Yes.
> Keeping with virtual domains - can you make Maildir --
> somthing like this:
>
> /var/spool/mail/vitrual_domain/user_name/Maildir
Yes.
But, how much features do you want? Store user data in a sql db? flatfile? LDAP? pop and/or IMAP access?
My favourite combination is Exim + Courier POP/IMAPd.