With the ConstantContact SDK, developers can integrate Email marketing data services into software and applications. Authored by Elijah Gaiter, this resource uses GuzzlePHP, an HTTP client that intends to simplify HTTP requests. Installation can be manual or via composer. See the source documentation available at http://constantcontact.github.io/php-sdk/
Google has released an updated Gmail API that functionally replaces the Email Settings API. The Gmail API includes a number of new endpoints that enable features previously unavailable through any Google API. Developers have access to filters, auto-replies, send-as aliases, and more.
Google API updates include My Business API and Calendar Resource API. The My Business API is a new API to manage your business listings online. The Calendar Resource API manages resources that are managed by users in their meetings. It replaces the now deprecated GDATA Calendar Resource API.