Internals

• Data Model for metadata (Cassandra)
• Labels and Markers are used instead of Folders and Flags
• Blob storage
• Encryption

APIs

• REST API
• LMTP LDA
• POP3
• … more to come (IMAP, etc.)

Operational

• Installation, configuration and running
• Monitoring

Roadmap

• Native support for message threads
• Built-in filtering engine based on SIEVE protocol
• Built-in search engine
• IMAP support (by porting one of the existing servers)