Camel is a mail access library that provides a complete, portable, and object-oriented framework for reading, writing, sending, and storing mail.

Using libcamel

Call camel_init() before using the library, and camel_shutdown() when done.

The main entry point to the Camel library is the CamelSession, it is the main application context and must be subclassed.

Core mail handling

• CamelAddress, CamelInternetAddress, CamelNNTPAddress — address parsing and encoding.
• CamelDataWrapper, CamelMimePart, CamelMimeMessage, CamelMultipart — the structured MIME message interface for reading and creating messages.
• CamelMimeFilter — stream processing modules for encoding, character set conversion, and more.
• CamelMimeParser — the core MIME parsing engine.
• CamelStream and subclasses — abstract I/O streams.
• CamelOperation — progress reporting and cancellation.

Writing a provider

• CamelProvider — the provider descriptor loaded from its shared libs.
• CamelService, CamelStore, CamelTransport — base classes for providers.
• CamelFolder, CamelFolderSummary, CamelFolderThread — folder and message management.

Miscellaneous API

• CamelCipherContext, CamelGpgContext, CamelSMIMEContext — encryption and signing.
• CamelSasl — pluggable SASL authentication mechanisms.
• CamelFilterDriver — rule-based message filtering.
• CamelOfflineStore, CamelOfflineFolder — offline operation support.
• CamelVeeFolder, CamelVeeStore — virtual (search-based) folders.

The camel_mime_utils.h header provides a wide collection of MIME and RFC 822 related utility functions used extensively throughout the library covering:

• Character class detection — a fast, table-driven set of macros for classifying individual characters according to RFC character classes (atoms, LWSP, tspecials, etc.).

• Content-Transfer-Encoding — highly optimised base64, quoted-printable, and UUencoding encoders and decoders.

• Raw header parsing — low-level tokenisers for MIME headers.

• Structured header handling — parsers and formatters for Date, Address, Content-Type, Content-Disposition, Content-ID, References, and Newsgroups headers with full RFC 2047 support.

• Header folding — utilities for folding and unfolding long header values according to RFC 2822.

Many of these functions represent years of production mail-client testing and are highly optimised. For most purposes, the higher-level interfaces on CamelMimePart, CamelMimeMessage, and CamelInternetAddress should be preferred.