This library written in PHP provides access to the SendGrid Customer Subuser API in PHP. The SendGrid Customer Subuser API allows developers to integrate user management functionality into their applications.
Email-list.com provides email marketing and social media tools for businesses. Recently the company announced an Email List API that gives visitors to your website access to counts and quotes on email lists.
DokDok, a Montreal-based startup, has had an email attachment management application on Google Apps some time. To make this work, it made an API to use internally that intelligently uses email accounts as if they were datastores. Recently, the company announced that this API would be renamed Context.IO and available to all.
Campaigner, leading email marketing services provider, has launched the Campaigner Elements API. The Elements API is intended to be integrated with analytics platforms to gain greater insight into subscriber behavior. Creating targets for email blasts is step one. The Elements API makes step two easier: narrowing focus to potential customers.