Stumbled upon this today and thought I'd share for those interested.
Since gmail's pricing changes, there have been a few threads which touch on "roll your own" alternatives. While the setup looks a bit complex for this, it actually looks quite good with a very pleasing UI for admin and end user alike.
http://modoboa.org/en/features/
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Modoboa is a mail hosting and management platform including a modern and simplified Web User Interface. It provides useful components such as an administration panel or a webmail.
Modoboa integrates with well known software such as Postfix or Dovecot . A SQL database (MySQL , PostgreSQL ) is used as a central point of communication between all components.
Modoboa is developed with modularity in mind, expanding it is really easy. Actually, all current features are extensions.
It is written in Python and uses the Django , jQuery and Bootstap, from Twitter frameworks.
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