Just when we thought that Gmail was stagnating, the big G rolled out upgrades that delighted power users: IMAP access, and a speedier, developer-friendly interface. As makers of the Better Gmail Firefox extension, we were psyched to get a personal heads-up from Gmail's Product Manager, Keith Coleman, alerting us to the revamp so we could update the extension. In addition to wrangling third-party developers to update their code, Coleman took time out of his busy day to answer some of our burning questions about the recent changes at Gmail. After the jump, hear what he has to say about IMAP, LDAP, Greasemonkey, the iPhone, and other third party Gmail clients, apps, and development.

Lifehacker: Gmail's IMAP support is a HUGE move forward for web-based email, something no other free webmail has offered. What made Google decide to offer IMAP? Is there any possibility of LDAP access to contact information in the future? (Editor: LDAP works similarly to IMAP in that it syncs your contacts to your address book, versus just exporting them.)

Keith Coleman, Gmail Product Manager: One of our core philosophies at Google is that users' data should never be held hostage. In the case of Gmail, users should be able to access their mail however and wherever they want. We started down this path soon after Gmail launched—in 2004 we added free POP access and auto-forwarding. POP let users get their mail on mobile devices and desktop clients. Auto-forwarding let people do useful things like filter mail and forward the most important messages to their phones, and even made it easy for users to switch away from Gmail to another email service if they chose. Millions of people start using Gmail each month, and many of them tell us how hard it can be to switch email accounts, particularly when switching from a service that doesn't offer POP, IMAP or forwarding. We didn't want Gmail users to have to go through that if they ever wanted to move away.

POP and forwarding were a nice start, but the downside of POP, as you know, is that you often end up having to read your mail twice—once on your mobile device or desktop client and again on the server. IMAP solves this by keeping mail in sync across all clients and devices. It provides a good user experience in classic email clients, so for webmail services, particularly those that rely on ad revenue, there's a risk that users may switch away from the web interface to desktop clients. Our belief is that if we make the Gmail web experience good enough and fast enough, people will choose to use it over other clients. This was an unknown when we launched POP, but it turned out to be right—most Gmail POP users use POP in addition to, not instead of, the web interface. We've taken the same approach with IMAP, giving users more choice and better email experience.

Your LDAP suggestion is an interesting one. We currently offer a way to import and export contacts, but don't yet provide an API like LDAP.

Lifehacker: That's interesting—counterintuitive, even—that users visit Gmail's web interface in addition to (rather than instead of) getting their email via POP. Thing is, POP's been offered by lots of web-based email services for years now, but not IMAP, and IMAP is not new. From what I understand of email-fetching protocols, the nature of IMAP is that it's more resource-intensive than POP (due to the constant reading and writing back to the server). So I always assumed that was the reason why no free web-based email service offered it. Do you think that's true? Or was it a matter of timing—did the iPhone launch play in?

Coleman: IMAP is something we've wanted to launch for a long time. It is a more complex protocol than POP, so took some time to implement, particularly given some of the work we did to make IMAP folders map well to Gmail labels. Resource usage wasn't a major factor in the decision to launch it—we knew a lot of users would love IMAP (including many new iPhone owners) and were eager to get it out as soon as it was ready.

Lifehacker: Gmail's recent upgrade not only improves performance, but it includes a Greasemonkey API, virtually inviting developers to modify Gmail's interface. As a Gmail extension developer myself, I'm thrilled! But I imagine Greasemonkey scripts and extensions only cause more headaches and work for the Gmail developers, and only benefit a small, demanding, power user base. Why did Google decide to go this way?

Coleman: We like to see and support innovation. Greasemonkey is a powerful tool in that it lets developers extend any web site. The downside, of course, is that because it extends sites by directly modifying the source code, rather than using stable APIs, extensions written in it are fragile to changes in the source code, and can even cause the host sites to break. As you point out, this can definitely be a headache, particularly when users hit bugs and can't tell whether the site is broken or the extension is broken.

It's inevitable that developers will want to use Greasemonkey to extend the products they use and like, so we thought we'd try to help make their extensions a bit more robust by providing a more stable API. The Gmail Greasemonkey API is still experimental—we're going to see how it's used and how helpful it is.

Lifehacker: Does the experimental API help Google track how it's being used?

Coleman: Right now it is purely a set of convenient wrappers on top of the code.

Lifehacker: You contacted developers (including myself) before the new Gmail upgrades rolled out to help us prepare our scripts and extensions for it. About how many developers were in the loop? How did you choose who to contact?

Coleman: Google is a data-driven company, so normally in situations like this we'd measure the number of active users running each extension and focus on those most frequently used. With Greasemonkey and other Firefox extensions, we don't have the ability to measure usage, so we did our best to identify the most popular extensions. We scanned through addons.mozilla.org, userscripts.org, and blogs that mentioned Gmail extensions. It wasn't always easy to find contact information for the developers, but we were able to reach some of the authors and give them early access to the new code.

Lifehacker: My fellow developers may kick me for asking this, but I must. Extensions and user scripts that do things I imagine Google doesn't love—like hide ads, or use Gmail's storage as a file drive—have never gotten a takedown notice from Google, as far as I know. Any comment on that?

Coleman: We like to see innovation—users trying new things—though of course don't condone violations of the Gmail terms of use. We're particularly concerned with abuse of the service that could affect the experience of other users.

Editor: For the record, Better Gmail does not include scripts that violate Gmail's terms of use.

Thanks so much to Keith for taking the time to give us a little peek behind the curtain at Gmail.

Tags: email | exclusive lifehacker interview | feature | gmail | greasemonkey | imap | iphone | top