I just created a repository on Gitorious for a client-side IMAP4 library. The project is luaimap and I’ve published it under the MIT license. The project consists of two files: imap4.lua is the actual library and checker.lua is a sample program that checks an IMAP account for new mail using the library. The library minimally requires luasocket to establish a basic connection. To establish a TLS connection luasec is also required.
The library implements all IMAP commands except ‘AUTHENTICATE.’ I’ve only tested it against a Dovecot server, so consider it very green. For now, it is a synchronous implementation: commands are sent and return a response from the server for the command. Going forward, I intend to add support for the AUTHENTICATE command and look at trying to take advantage of command pipelining.
Anyone intending to use it should read RFC3501, the document on which the library is based. The intention of the library is to handle the protocol related details of IMAP4rev1, not to enforce IMAP4 client side design practices.
To use it, simply install the file in a project directory and use a line like:
local imap = require("imap4")
To make it available on the system, copy the file in a path that exists in lua’s package.path variable. On my system, a debian/testing setup, I’ve installed it to /usr/local/lib/lua/5.1/.