[Dovecot] Maildir owner importance

[Peter Lacey]

> How important is to have all the directory tree owned by the same user
> group (virtualmail:virtualmail) ?

My understanding (which could be wrong) is that it's pretty important.  
First, as a rule of thumb, nothing should be owned by root that doesn't 
have to be owned by root.  When Dovecot is writing mail to a directory, 
it assumes the user ID of the recipient.  In your virtual setup you 
probably don't have local users, so Dovecot will change to the user id 
returned from your database/ldap query, or, if using LDAP and you want 
to, to the user specified in user_global_uid setting.  In either case, 
that user should be the user who owns the directory tree (virtualmail) 
and not root.  Your setup can work, of course, if you give the 
directory read/write permissions for group and world, but why would you 
want to?

- Pete