We've blogged about the LEMONADE Profile for mobile messaging on a number of occasions and we've committed to incorporating LEMONADE into our products with Release 12 of our software, now only a few weeks away.
Whilst the profile contains many elements (and you can read more about them in a whitepaper here), there are three specific benefits that attract the most attention:
- Push email
- Forward without download
- Efficient re-connection and re-synchronisation
Push email is a term that is often miss-interpreted. The actual user requirement can be summed up by the phrase "Whenever a new message is delivered to my mailbox, I want to be notified 'immediately' that the message has arrived."
The Lemonade working group started from the supposition that IMAP and SMTP are already a good combination for the provision of mobile email, when there is ongoing activity between the client and the server IMAP will automatically inform the client of the presence of new messages.
The IMAP IDLE command, which is a widely implemented standard extension to the core IMAP protocol and contained within the LEMONADE Profile, ensures that the server will inform the client of new messages even when there is no other activity taking place between client and server.
IDLE maintains the connection by issuing a 'NOOP' command, usually every 15 minutes, to ensure that the connection isn't disrupted by a timeout (such as an IMAP server timeout, TCP connection timeout or NAT gateway timeout).
IMAP -IDLE is a very efficient way of offering all the benefits of push email with substantial implementation, deployment and performance advantages over alternative approaches to solving the user requirement outlined above. You can read more about IMAP-IDLE in a whitepaper on the Isode website: "IMAP IDLE: The best approach for 'push' email."
We'll blog more about our LEMONADE-related changes to M-Box and M-Switch as the release date for r12 approaches.