For maniacs who have not yet switched their mail operations to the ever growing gmail storage offer, a few opensource web based email players will provide efficient ajax webmail operations. Choosing between IMAP and POP3 shouldn't be a problem but bear in mind the basic difference between them : IMAP stores emails on the mail server while POP3 needs the client to perform this. As a result you will find it harder to implement POP3 storage from the client perspective, and this is why it took a long time for companies such as AfterLOgic to release their client. WebMail Lite is a very efficient web client that comes opensource with multiple templates and complete source code. In its time we reviewed RoundCube, that only works with IMAP. Same for new player biuCentrax Mail Center, image above, that demosntrates extjs library integration. Of course, for non ajax playing you can count on the old but reliable Horde framework IMP client.