Lime is a mail library for Clojure. Development is currently focused on designing an abstraction for scripting SMTP sessions as a client. Future development will include further abstractions on top of SMTP, and perhaps other mail protocols.
One key feature of Lime is that it does not depend on JavaMail. The primary goal of the project is to give you full access to the protocols and data structures, at the abstraction you want to use. For example, if you want to extend SMTP, as allowed by the specification, then the tools will be available for you to do so.
That said, Lime is still very young and in development. The focus is on client-side SMTP, so keep that in mind when browsing the code. If you're looking for a fully featured and production-ready SMTP client library, please check out Postal. It is an excellent wrapper for JavaMail.
Here is a snippet from the Lime blog about the motivation to start building Lime:
At the time of this writing, Clojure doesn't have any built-in mail libraries. Also, all of the third party mail libraries that I have seen depend on JavaMail. This is fine for anyone who wants to simply send mail using the JVM. The problem is that the JavaMail API was built for Java, which leaves much to be desired in terms of expressiveness and extensibility in a Clojure environment. I believe there is an opportunity for a better and simpler solution to send mail with Clojure. Sending mail should be as simple as a function call, but it should also be simple to dig into the protocols and use them to their fullest extent. There also is more than just the JVM to consider, and I believe having a common mail library that can easily be ported to other Clojure platforms would be incredibly useful.
Please report issues in the issue tracker. Contributions are encouraged to be made in the form of pull requests, but since we are still working to get 1.0.0 released, please start a discussion on what you would like to work on. Other then the issue tracker, you may join us on the mailing list or on IRC at #limemail in FreeNode.
Copyright (c) 2011-2013 Jeremy Heiler. Distributed under the Eclipse Public License, the same as Clojure. See COPYING.