For as long as I can remember, any time people talked about their Gmail wishlist, it always included IMAP support -- finally, according to the Download Squad, this functionality finally exists.
What is IMAP? Basically it is a different way email clients like Outlook can manage your email. There are two different methods that most clients support: POP and IMAP.
POP, has been supported since Gmail was launched. It basically downloads all messages to your local machine, then messages are read and managed locally. In contrast, when users use IMAP, all the messages exist and are managed directly on the server. This means that if a user move a message to a different folder, replies to or deletes messages, or anything else, everyone who subscribes to that IMAP account in their email client will always be in the loop.
This can be very useful if you have a shared company-wide email address, like "sales", and you want to prevent multiple sales people from replying to the same message, or if you have a personal email address that you check on multiple machines. Thank you Google for finally giving this feature to us.
[image from Search Engine Land]