mail-parser is a WIP command-line utility with the goal of parsing Maildir-stored e-mail files.

The early versions of the program will use parsing code written from scratch to familiarise myself with the e-mail and related RFCs that specify how e-mails should be interpreted.

Later versions may rely on a library to handle some of the parsing.

• mmap (as read-only) the file specified in a command-line argument.
• Index the line-endings of headers and where the message body (if any) begins.
• Print the header names.
• Parse the MIME-Version header.
• Parse the Content-Type header.
• Print the body if there is no Content-Type header.
• Print the body if Content-Type: text/plain.
• Parse the first level of Content-Type: multipart/alternative and index the boundary delimiters.
• Parse nested levels of multipart MIME message bodies.

The current source code should compile with gcc if the necessary C libraries are available:

gcc c-mail-parser.c -o mail-parser

The current code creates a program that requires one argument: a single e-mail file to parse.

./mail-parser path/to/email-message-file

As the program is being designed for files stored in Maildir format mailboxes, on Linux systems where the LDA is dovecot, files with lines terminated by LF will likely be better tested than those with CRLF line endings.