Mailbox API 2.0

Welcome to the second generation of our Mailbox API. This is an HTTPS-only API, with OAuth 2 authentication and CORS support running at:

It uses JSON for requests, responses and error messages. The responses typically include resource links which should help you explore the API and free you from composing URIs by hand.

Previous API version

The V1 API is still supported in a maintenance capacity and only security patches will be backported. All new features will only be added to V2 from now on, if there are any features you’d like to see included in our Mailbox API 2.0, be sure to let us know. A summary of the main differences between the versions is available here.


If you’re interested in joining the Mailbox API 2.0 beta, please let us know, we can enable it for you.

The API is currently running in Beta mode and supports almost all resources that V1 supported excluding Webhooks and Workflows. Support for both of these will be added before we enable the API for all our customers. The Beta status means that some of the endpoints could miss a feature or two, though our goal is to close this gap as soon as possible:

  • Auto Reply does not work 2.0 at the moment


While we won’t introduce any breaking changes, we plan on adding new features and new endpoints over time. Our changelog can be monitored to see when and how the API was updated.


We have also been working on example PHP and Java SDKs, which should be available before the API is released to all customers.