There was a time when people rarely used more than one computer and now people rarely use only one computer. Almost everybody access to Internet from different terminals and devices. The problem is, with a POP access, the changes made to emails from one device are not synced across the others. If an email is moved to starred folder from iPhone, the user will still see it in Inbox while accessing the email account from desktop.

Now IMAP is here to solve this problem. IMAP – Internet Message Access Protocol would update email information though out all the devices and changes made from one would be reflected in all. Gmail team has started rolling it from October 24, 2007. Find more information about IMAP and Gmail at Gmail: Help Center and Official Gmail blog.