The Runbox Webmail service requires cookies to be accepted by your browser for it to function. A cookie is a small piece of data sent from our web servers to your web browser and stored on your computer.

Like many websites, Runbox uses session cookies which are used to keep you logged in to your account and remember certain details throughout your session. Without authentication and session cookies the server would not know if it had seen your browser logged in before as you navigate from one page to the next, and you would have to enter you username and password every time you click on a link in the Webmail.

This is the only reason Runbox uses cookies as we are very conscious of protecting your privacy. If you see the “cookies are not enabled” warning on the log in page, please enable cookies in your browser. Alternatively you can add an exception for the Runbox domain you are using ( or so that your browser can accept cookies from our servers.

Many people block cookies for privacy reasons as some cookies can track which websites you visit (tracking cookies). That information can be used by website owners for various purposes including, but not limited to, targetted advertising of goods and services. Runbox does not use tracking cookies.

List of Runbox cookies

mysessid: This is the default web session cookie. It is used to store internal variables containing values about the state of the session such as the user’s IP address, current URL, current webmail folder, open webmail folders, etc.

device_id: This cookie is used by the authentication service to bypass 2FA for known devices. Itis created when user creates/registers a new trusted device in Account > Account Security > Two-Factor Authentication.

Runbox::AuthCookie_Runbox: This authentication cookie is updated on every web request, and determines whether a request is authenticated.

user_session: This cookie is used to allow users to list any other session that has been active for their account, in Account > Account Security > Sessions.

webserver_cluster: Used to tell the servers which cluster of web servers the user should be directed to.