It was created by DokDok (one of our enterprise startups to watch in 2011), which used the same API to build its attachment management app. "Up to now, 'email integration' in CRM or productivity apps meant adding an obscure BCC on outgoing emails and forwarding incoming emails; a manual, repetitive and error-prone process," says DokDok founder Bruno Morency.

Use cases include integrating email with other applications, such as CRM (like DokDok's integration with Highrise), document management systems, calendars and to-do lists.

We've covered the concept of email-as-a-platform a few times in the past. GMailr, an unofficial JavaScript API for Gmail, is another example of an open platform for email innovation.