[Dovecot] Hybrid of linux user accounts and virtual user accounts configuration

[Derek Winterstien]

So some system users have their email forward to 
Maildir in their /home/user directory 
(virtual_alias_maps) for their domain 
. This I 
have working! And the rest are non-system users, 
ie virtual users listed in a plain text file and 
their MailDir will be in /home/vmial/domain.com/user/

The virtual user part is working 100% with 
postfix and dovecot accepting mail for each 
virtual alias and system account holders popping in to retrieve their mail.

The second part is working 50%.  I have email for 
virtual users going into 
/home/vmail/domain.com

  where they are supposed 
to go.  Now, I am very confused on how to 
configure dovecot to allow folks without system 
accounts to login and retrieve their email.  I 
have been going through one guide after 
another.  When I start changing things I break 
the first working part, the system accounts being 
able to get their mail.  Changes to dovecot.conf 
to get the second working negatively impact the first.

Also, a lot of documentation is out of date, which further complicates matters.

Postfix/Dovecot:
Postfix version: 2.6.6
Dovecot version: 2.0.9