Maildir

A maildir manipulation library for Elixir

Warning

It is very much a work in progress. Things may breaks without any warning! Everything details after this may not be implemente yet. I'll update this file as the work progress.

Usage

A maildir is simply a string representing a path to the maildir folder.

iex> my_maildir = "/home/doctor/Maildir"

Still, there is an Maildir.open function defined to check that the path given indeed contains the 3 folders cur, new, tmp. This function return the path given if it is indeed a maildir, or :error otherwise.

iex> my_maildir = Maildir.open("/home/doctor/Maildir")
"/home/doctor/Maildir"
iex> my_maildir = Maildir.open("/home/doctor/not_a_maildir")
:error

A message (Maildir.Message) is defined as follow:

iex> defmodule Maildir.Message do
...>   defstruct maildir: nil, folder: :tmp, uniq: nil, info: nil
...> end

The maildir field is effectively the path to the maildir, folder is one of the :cur, :new or :tmp folder, uniq is the uniq part of the message, and info its info part.

The content of a message is not kept in memory, it is written to disk as soon as it is created.

iex> Maildir.add("/home/doctor/Maildir", "Doctor! We need you!")
{:ok, %Maildir.Message{maildir: "/home/doctor/Maildir", folder: :new, uniq: "so_uniq_string", info: nil}}

The library does not assume anything about the content of the file, nor try to parse the message. That is the job of your e-mail parser.

Thus, creating or adding a message in the maildir will always works, as long as the content is not the empty string.

You can list all the new message in the Maildir:

iex> Maildir.list(my_maildir, :new)
[%Maildir.Message{...}, %Maildir.Message{...},...]
iex> Maildir.list(my_maildir, :cur)
[%Maildir.Message{...}, %Maildir.Message{...},...]

Processing a message move it from new to cur:

iex> Maildir.Message.process(my_message)
:ok

And everywhere a function take a message struct as argument, you can pass a string representing the message fullpath instead:

iex> Maildir.Message.process("/home/doctor/Maildir/new/1111.2ec459f.tardis")
:ok

Steps

1. Implementing the original Maildir specification
2. Implementing the Maildir++ extension
3. Implementing the Dovecot Maildir extension
4. Profit

Resources

• Wikipedia: https://en.wikipedia.org/wiki/Maildir
• Maildir original specs: http://cr.yp.to/proto/maildir.html
• Maildir original man page: http://www.qmail.org/qmail-manual-html/man5/maildir.html
• Courrier IMAP Maildir++ specs: http://www.courier-mta.org/maildir.html
• Maildir++ quota extension: http://www.courier-mta.org/imap/README.maildirquota.html
• Dovecot maildir implementation: http://wiki2.dovecot.org/MailboxFormat/Maildir