dovecot - Aug 2013 - Mailbox Format

Hello List,

I'm in the process of implementing a new mail server environment from
scratch. I was  wondering, what mailbox format is recommended?

I have been using maildir format for my other projects. I would like to use
some format that provides Single Instance Storage.

I'm using postfix 2.11 and will use lmtp. I will be using dovecot 2.2.5
(Latest) version. I'm not planning on using NFS (if that matters) and will
use dsync to backup mails to another server.

Thanks in Advance
Vijay Rajah