IMAP IDLE Lift Module

Provides push-like email: your Lift web application can be notified when email arrives, via the IMAP IDLE feature.

Using this module

1. Add the following dependency to your SBT project file:

    // For Lift 2.5.x (Scala 2.9 and 2.10):
    "net.liftmodules" %% "imap-idle_2.5" % "1.0"
   
    // For Lift 2.6.x (Scala 2.10):
    "net.liftmodules" %% "imap-idle_2.6" % "1.1"
   
    // For Lift 3.0.x (Scala 2.10):
    "net.liftmodules" %% "imap-idle_3.5" % "1.0-SNAPSHOT"
   

2. Set your IMAP login credentials in your props file, e.g.:

    $ cat src/main/resources/production.default.props
    imap.idle.mail.user=you@yourdomain.com
    imap.idle.mail.password=trustno1
    imap.idle.mail.host=imap.gmail.com
   

3. In your application's Boot.boot code:

    import net.liftmodules.imapidle._
    ImapIdle.init { m : javax.mail.Message =>
       println("You've got mail: "+EmailUtils.dump(m))
       true // delete the email on the server
    }
   

...which will dump the contents of the email to your console and then delete the mail.

If you're doing persistence in the Message => Boolean handler, ensure you initialize Record/Mapper before you ImapIdle.init because init will try to connect and start processing any emails that may be waiting.

Example Scenario

Using this module you can provide a way for users to email in content via an address tag. Here's how... listen for messages at a single email address, such as account@example.com. Users email content into account+UNIQUE_ID@example.com. In your handler, extract the recipient from the message, parse out the UNIQUE_UD. Finally, do whatever you need to do with the content based on the UNIQUE_ID.

Gotchas

• For this module to work, the IMAP server must support the IDLE command. Tested servers: Google mail (imap.google.com).

• Your email account must be set to enable IMAP access. In Gmail this is Settings > Forwarding and POP/IMAP.

• If you're deploying under Jetty 6.1.26 or earlier, you will need to replace $JETTY_HOME/lib/naming/mail-1.4.jar with mail-1.4.1.jar or later (1.4.4 is the version that ships with Lift). Or... in some way resolve this w.r.t to Jetty classloader.

• This code depends on a com.sun class in EmailUtils, meaning it may not work under non-Sun derived JDKs.

• If your application is partitioned from the IMAP server it may take 30 minutes for the IMAP IDLE code to detect this and re-establish a connection to collect messages.

How this works

The module creates a Lift actor called EmailReceiver. Set the actor up by sending Credentials, the Callback to execute of type Message => Boolean, and finally the 'startup message. When email arrives, the callback is executed and if it returns true, the email is considered handled and deleted.

Debugging

If you want to see what javax.mail is doing, set mail.session.debug=true in your Lift Props file.

If you want to interact with EmailReceiver from the SBT console, here's how:

sbt> console

import net.liftweb.common._
import net.liftweb.util._
import net.liftmodules.imapidle._

net.liftweb.util.LoggingAutoConfigurer()()

EmailReceiver ! Credentials("me@mydomain", "letmein", "imap.gmail.com")
EmailReceiver ! Callback(EmailUtils.noopHandler)
EmailReceiver ! 'startup

// Interact with EmailReceiver as you like. E.g., perform a manual collection of mail:
EmailReceiver ! 'collect

To build from source:

First Install SBT and then...

$ git clone git://github.com/d6y/liftmodules-imap-idle.git
$ cd liftmodules-imap-idle
$ sbt
> compile
> publishLocal