Gmail is getting support for IMAP clients like Outlook, Thunderbird, and the iPhone. This means that Gmail users will no longer limited to the Gmail.com user interface or to the weak integration they can get from clients using the much more rudimentary POP email protocol.
There’s no word on the official rollout schedule for IMAP support. Some users have it, some don’t. I do. Don’t ask me why. To see if you have support, click on the “Settings” link and then see if you have a “Forwarding and POP/IMAP” tab.
If your account is IMAP enabled, these instructions will walk your through configuring your account and your client software.
Why does this matter? Because IMAP is a two-way email protocol. IMAP client applications can interact with IMAP servers, like Gmail’s, so data on both sides stays in sync. If you have multiple IMAP client apps, they’ll all show the same email messages (including indicating which messages have been read) as long as they stay connected. However, Gmail handles email differently from most standard email client software, so the integration will take getting used to. For example, if you move a message from one folder to another in your desktop email client (like Outlook or Thunderbird), the message’s label in Gmail will change to match — since Gmail doesn’t have folders, per se. Google’s IMAP behavior chart lists the differences.