Not everyone will appreciate it, but Google just upped the ante in the webmail game by rolling out unprecedented free IMAP access for Gmail. Beginning last night, Google began activating IMAP access to all Gmail accounts, and as of this morning plenty (but not all) users are reporting that IMAP access to Gmail is now possible. IMAP isn't a new technology, and it's certainly not loved universally. It does make Gmail that much more accessible on a variety of devices and from multiple locations, however, and it puts Microsoft and Yahoo in the position of needing to play catch-up.
Gmail has allowed access via the web interface or POP access for quite some time now. POP allows e-mail clients to download messages from the server, but doesn't reflect any changes on the server once the messages are manipulated on the client side. So if you download five messages, read four of them, and move three of them to other folders on your desktop e-mail client, those messages will remain unread and unmoved on the Gmail server. When you check the server again from a different device, you have to go through the whole process all over again with the same messages.
Such is not the case with IMAP—any changes you make on the client side are synced back with the server (when a connection is available), so that read items remain read and moved items remain moved on all devices checking that account. In other words, IMAP treats remote folders as if they were local, which is great if you use more than one interface for accessing and organizing your email (say, webmail from work, your iPhone on the road, and a mail client like Thunderbird at home).
Google has a help page up that explains the differences between POP and IMAP, along with instructions on how to set up the latter on your account. IMAP isn't pushmail, and it isn't known for being lightening fast. IMAP is the best widely-supported protocol for multiple access point usage, however.
IMAP not for the weak (servers)
IMAP has been slow to come to free e-mail services for a variety of reasons. In addition to the fact that most users of free email services have been happy with webmail clients and therefore don't care about IMAP, it generally requires more resources per active user on the server side. Because IMAP typically maintains connections between client and server, it requires more bandwidth and processing power to maintain per user. By enabling IMAP, Google is flexing its muscles.
IMAP also encourages users to store messages on the server over the long term—something that POP users do as well, but perhaps not as often or in such high volume, and certainly not in remote folders. IMAP access is thus enabling another way to get at the massive storage capacity offered by Gmail.
Gmail Product Manager Keith Coleman has another theory on why webmail services haven't made IMAP widely available, noting that most (including Google) are at least somewhat dependent upon advertising revenue from their web-based clients. "We thought that was a trend worth breaking," he told Ars. "Initial reaction has been great so far."
While this tidbit of news may not mean anything to casual Gmail users, it's a major feature addition for an otherwise free, publicly-available e-mail service. Not only does it come as a welcome addition to those who make heavy use of Gmail, it will also make a difference to businesses and institutions that use Gmail as part of Google Apps for your Domain. Lots of business users check their e-mail on various handheld devices in addition to a computer or two, so the addition of IMAP will make Google Apps for your Domain a much more attractive service for companies looking for comprehensive, yet easy, e-mail solutions.
While Yahoo and Hotmail have more or less caught up with Google when it comes to offering mass amounts of storage capacity, the addition of IMAP to Gmail will make a big difference in free e-mail services in the future—it likely won't be long before we see IMAP capabilities added to Yahoo and Hotmail, and perhaps even a smattering of smaller e-mail services vying for attention.
As mentioned at the outset, IMAP isn't universally loved. It can be slow, especially over wireless mobile data networks that barely escape dial-up speeds. Yet more access options can't hurt, and judging from reader reports we've received, many of you with mobile devices that support IMAP are already itching for Google to activate your account. If you try it out, let us know your experience in the discussion. We're currently finding the iPhone support to be excellent (over WiFi).