Best Self Hosted Alternatives to Proton Mail Bridge

DavMail is a gateway that exposes standard email, calendar, contacts, and directory protocols in front of Microsoft Exchange and Microsoft 365. It enables common clients to work with Exchange by translating IMAP/POP/SMTP, CalDAV/CardDAV, and LDAP requests to the underlying Exchange web interfaces.

Key Features

• IMAP and POP access to Exchange mailboxes (folder browsing via IMAP; inbox retrieval via POP)
• SMTP submission for sending mail through the gateway
• CalDAV support for calendars, including attendee scheduling and free/busy
• CardDAV support for syncing personal contacts
• LDAP gateway for Global Address List and personal contacts, enabling address auto-completion
• Cross-platform Java implementation, commonly used on Windows, Linux, and macOS

Use Cases

• Use Thunderbird, Apple Calendar/Contacts, or similar clients with Exchange without Outlook
• Provide CalDAV/CardDAV endpoints for devices and apps that do not speak native Exchange protocols
• Expose LDAP for directory lookups and recipient completion when composing email

DavMail is well-suited when you need standards-based interoperability with Exchange environments, including scenarios where access is available via web endpoints such as Outlook Web Access.