Ako Webmail Enterprise.
It is developed based on the open-source Ako Foundation Project. It has been modified to meet enterprise requirements for email servers including message routing, data storage, and security.
Must Read: Ako webmail
The article would have you believe it is an open-source variant of Exchange Server. But, there’s only one part where they describe what’s different about this software…
“It has been modified to meet enterprise requirements for email server including message routing, data storage, and security.”
…which doesn’t sound like Ako Webmail Enterprise is open source (or free) at all. The article really makes you think that some major corporation must have created it. But the only mention of an organization in association with this product is a company called Azetap.