Compatible Web Browsers
Compatible applications for our service
Our service supports a wide range of applications and browsers. This page serves as a central entry point to help you find the right combination of application and operating system for your requirements. In addition, you will find practical use cases and further documentation to facilitate integration.
Browser compatibility
We recommend using current browser versions for the best possible experience and security.
| Browser | Operating system | Notes |
|---|---|---|
| Google Chrome | Windows, macOS, Linux | Use the latest version |
| Mozilla Firefox | Windows, macOS, Linux | Use the latest version |
| Microsoft Edge | Windows, macOS | Use the latest version |
| Safari | macOS, iOS | Use the latest version |
Email clients
Our service supports both web-based and desktop email clients. The Thunderbird desktop version is recommended; older clients or untested applications are not guaranteed to be compatible.
| Email client | Operating system | Notes |
|---|---|---|
| Thunderbird Desktop | Windows, macOS, Linux | Use the latest version |
| Outlook Web / Desktop | Windows, macOS | Observe limitations with calendar integration |
| Apple Mail | macOS, iOS | WebDAV support required for calendars |
Practical use cases
Note: For external clients, an application password is required when two-factor authentication is enabled.
To make usage easier for you, we have compiled typical scenarios for different target groups:
For developers
- Open standard protocols (CalDAV, CardDAV) are available for calendar and contact synchronization.
- There are no native webhooks at mailbox, which means server-side event triggers or push automations are not directly supported.
For end users
Cross-device access:
mailbox enables synchronization of emails, calendars, and contacts across different devices, however only via standardized protocols:
- Emails: Synchronization via IMAP/SMTP in clients such as Thunderbird, Outlook, or mobile email apps.
- Calendars: Synchronization via CalDAV in supported clients (e.g. Thunderbird with Lightning, macOS/iOS Calendar, Android via DAVx⁵).
- Contacts: Synchronization via CardDAV in compatible clients.
Overview of CalDAV and CardDAV.
Calendar sharing:
Mailbox allows sharing calendars and address books with other users or via public links.
- Shared calendars are provided in iCal format.
- External recipients usually receive read-only access; changes by third parties are not possible.
- Use of sharing is client-independent, but only works in clients that support CalDAV/iCal.
By operating system
- Windows: Chrome, Firefox, Thunderbird Desktop
- macOS: Safari, Chrome, Firefox, Thunderbird Desktop, Apple Mail
- Linux: Firefox, Thunderbird Desktop
Notes on external applications
Our service does not support direct integrations with external applications or clients that have not been officially tested or approved. External tools without official compatibility may lead to limited functionality or errors, especially with email synchronization, calendar sharing, or API usage.
Please also note that we cannot provide support for this topic.
To ensure the compatibility of your applications, we recommend:
- Use recommended clients:
For desktop usage we recommend Thunderbird; for web access, current versions of Chrome, Firefox, or Safari. Other clients or older versions are not officially supported and may result in functional limitations.
By following these guidelines, you ensure that your setup runs stably and that all features of our service are available.
Glossary
Application password
A special password used to access external applications when two-factor authentication is enabled.
CalDAV
An open standard protocol for synchronizing calendar data.
CardDAV
An open standard protocol for synchronizing contact data.
DAVx⁵
An Android application for synchronizing CalDAV and CardDAV services.
iCal format
A standardized file format for the representation and exchange of calendar information.
IMAP/SMTP
Standard protocols for receiving (IMAP) and sending (SMTP) emails.
Two-factor authentication (2FA)
A security mechanism that requires a second factor in addition to the password for login.
