Posted by Wesley Chun, Developer Advocate, Google Apps
Last summer, we launched the new Gmail API, giving developers more flexible, powerful, and higher-level access to programmatic email management, not to mention improved performance. Since then, it has been expanded to replace the Google Apps Admin SDK's Email Migration API (EMAPI v2). Going forward, we recommend developers integrate with the Gmail API.
EMAPI v2 will be turned down on November 1, 2015, so you should switch to the Gmail API soon. To aid you with this effort, we've put together a developer’s guide to help you migrate from EMAPI v2 to the Gmail API. Before you do that, here’s your final reminder to not forget about these deprecations including EMAPI v1, which are coming even sooner (April 20, 2015).