INNOVATORS OF THE NET: JOHN MYERS AND IMAP

"Well-known

and well-

respected

in the IETF,

John has

contributed

to a number

of Internet

standards in

addition to

IMAP4."

All that email traffic calls for scalable, reliable, manageable, high-performance messaging solutions for Internet Service Providers (ISPs) and businesses. John Myers, principal engineer and messaging architect at Netscape, is working to make sure that the mail gets through quickly and securely. John was part of the Internet Engineering Task Force (IETF) working group that proposed Internet Message Access Protocol (IMAP), version 4, as the new Internet standard for reading email from the server. He wrote the first server software released that fully implemented IMAP4, and he managed the deployment of that software while he was working on messaging and security at his alma mater, Carnegie Mellon University, in Pittsburgh, Pennsylvania.

Well-known and well-respected in the IETF, John has contributed to a number of Internet standards in addition to IMAP4. He wrote the experimental Internet Messaging Support Protocol (IMSP), which evolved into the Application Configuration Access Protocol (ACAP), cowritten with Chris Newman. IETF adopted ACAP in 1997 as an Internet protocol for accessing client program options, configurations, and preferences remotely. John also created a security framework, called the Simple Authentication and Security Layer (SASL), used by IMAP, ACAP, and other Internet protocols. His current work includes the SMTP Authentication specification now being offered for IETF standardization and a revision of the IMAP4 Access Control List (ACL) extension spec.

"I've known I was going to be in computers since I was in seventh grade, when my father got a TRS-80 in his office," John says. Originally from Gainesville, Florida, he received his bachelor of science degree in math (computer science track) from Carnegie Mellon and went on to work at the university as a systems programmer from 1990 to 1996. It was during those years that he began his work on Internet email and security standards. In 1996 Portola Communications recruited John as director of engineering because the company had heard about his impressive work at Carnegie Mellon. At Portola, John worked on commercial IMAP4 server software that by the spring of 1997 literally screamed, getting in some areas ten times the performance of other servers. It's no secret that we were delighted to grab John when Netscape acquired Portola Communications in June 1997, after its stellar start-up stage.

At Netscape, John has put his tremendous knowledge of the messaging industry and protocols to work on Netscape Messaging Server and Netscape Messaging Server Hosting Edition. John's a great team player - he's been a dedicated advocate of security and has worked closely with the client group and the security group. "I like the fact that I can have an impact on things within Netscape, and a rather far-reaching impact," John says. "I talk to other groups, and they take suggestions. It's based on merit here, and there's a certain amount of meritocracy. If you've got good ideas, people listen to you."

John's a modest kind of guy, not much inclined to talk about himself or his work, but a not-so-closely-guarded secret about him is that he harbors a real passion for ballroom dancing. We have proof. Word is that he's so good at it he even teaches it sometimes.

I recently had an opportunity to sit down with John and talk about IMAP's past, present, and future.

I did several things to improve the Andrew Messaging System's scalability, to keep it from falling over, but it was clear that we had to replace it with something. Its strong point was that it stored all the mail on the server, so people could move from machine to machine. They could access their mail at work, or they could go from one lab to another, or they could go home and access their mail. There wasn't anything comparable out there, and it's very hard to take features away from users.

So I looked through the IETF Request for Comments (RFCs) that were available at the time, especially those for accessing stored mail, and I found, basically, only two possible protocols. One of them was Post Office Protocol (POP), which was far too simple, because it doesn't allow multiple folders on the server; everything's downloaded. The other was IMAP (version 2.0), written by Mark Crispin of the University of Washington, which was at least the start of something that we would need in this new system.

I got in touch with Crispin and started working with him and some other people at the University of Washington. Then we took IMAP into the IETF and came up with IMAP4, which was approved as a Proposed Standard in 1994. The initial RFC for IMAP4 was revised in 1996 and in 1998.

Concurrently with the IETF work, I wrote an IMAP4 server that was designed to be scalable. That was the Cyrus server. We named it after Cyrus the Great of Persia (599-530 BC), the Persian emperor who instituted the first scalable postal system - or so we thought. Later research showed that it was actually Darius, not Cyrus, who instituted the postal system. I believe Cyrus came later. It may have been Cyrus who first instituted secure messaging, sending spy reports inside dead rabbits - I'm not up on all the details.

In the summer of 1996, I got the offer to go to Portola. I had finally gotten the Cyrus server to the point where we were starting deployment, and the Portola offer was basically an opportunity that was too good to turn down. By the spring of 1997, Portola had an IMAP4 server that was far faster than anything else available. We were getting ten times the performance in some areas. That's when Netscape bought Portola. So I came to Netscape in June 1997, when the merger was complete, to integrate the Portola codebase into Netscape's next-generation messaging server. It performs better than anything else we know about. We introduced it at the Electronic Messaging Association conference in April 1998.

What do you see as the key features of IMAP?
There are two primary ones. The first is location independence, meaning the mail is stored on a server, so you can access it from home, from on the road, or from work. The other is the feature called disconnected use, which means that you can download a copy of your mail to your laptop and then disconnect from the network. You can then read your mail, reply to it, and make changes to the folders, all while on a plane or in some other place where you don't have a network connection. When you reconnect to the network, your replies are sent out and the changes you made on the client are applied to the server.

In addition to these two features, IMAP is on the Internet standards track, so it can work across a variety of clients and servers.

What other features make IMAP unique?
The search capability is one standout. With IMAP you tend to leave your mail on the server, so the client only downloads what it needs, and doesn't normally have enough of the mail to do searches locally. But the client can ask the server to perform a search in the headers or the bodies of messages, and the search happens on the server, which replies as to which messages match. So you can say, "I'm looking for messages from John Myers, after last Thursday, which came with the word 'IMAP' in the body." You don't have to pull 3000 messages down to the client to find the one you're looking for.

IMAP is also great if you commonly find yourself in situations where you want to preview your incoming messages and selectively download them. Since IMAP clients, such as Netscape Communicator 4.5, essentially download only headers with the basic information - subject, sender, date, and time - you can pick and choose which messages to actually download. And if you've got a message with a large attachment, you can even download the text portion of the message and leave the attachment alone.

How else is IMAP poised to change the email marketplace?
I think IMAP will eventually replace POP. Legacy systems take a long time to completely disappear, so POP will be around for quite a while, but all the new features are going to be in IMAP. IMAP is great for businesses, because it allows them to centralize their mail storage. So instead of having to back up mail on hundreds of PCs, the mail's in a central place. If a company wants to apply an expiration policy so that three-year-old mail isn't lying around on someone's PC, they can. Business users can connect into their company's email service from anywhere - office, home, or on the road - thereby getting universal access to this mission-critical business service just as they do with the telephone.

IMAP is an enabling technology. New applications can be built using it. The fact that IMAP allows you to query the server in a very efficient way makes it possible for applications to check for messages and download them on demand. Additionally, IMAP servers handle concurrency so multiple applications can be operating simultaneously on the same files. An example of a killer IMAP application is Unified Messaging, which gives end users access to all of their messages regardless of type, location, or communication device. In other words, Unified Messaging uses a universal message store to store email, voice mail, and faxes, all of which can be accessed from any type of device, ranging from telephones to PCs to faxes. For example, someone might be sending me email at the same time my voice mail system is reading my email to me (using text-to-speech technologies). Because the voice mail system is using IMAP to access the message store, issues of concurrency are handled by the Messaging Server. Netscape is one of the few companies that has a Unified Messaging solution that's ready to deploy now. It's based on Netscape Messaging Server 3.5 and Amteva Unified Messaging Plus Release 2.0, and it supports all the major industry standards, including LDAP, IMAP4, SMTP/MIME, VPIM, and HTTP/HTML.

I think IMAP is going to be a big hit with ISPs and telcos because it gives them the opportunity to offer valuable services that can provide high returns and lock in customers. For ISPs, IMAP reinforces customer retention and loyalty. That's because with IMAP, users keep their mail folders on their ISP's server to get the location-independence and disconnected-use features, so users have a greater incentive not to switch ISPs. Netscape has a lot of ISP and telco customers - Netcom, Bell Canada, Telstra, France Telecom, and Telefonica, to name just a few.

Email is the Number 1 application of the Internet. The native Internet mail systems are going to push out proprietary systems, and the main reason for that is security. Currently, you've got a lot of proprietary mail systems that use gateways to get the mail from the proprietary mail system to the Internet and then over to a different organization. A gateway, by definition, changes a message. The problem is that once you add S/MIME encryption or digital signatures, you can't use gateways, because once you sign the message, if anything changes the message, it destroys the signature. Or if the message is encrypted, a gateway can't even see the message content, much less change it. People who want to use mail with security features are not going to be able to use proprietary software; they're all going to have to convert to the Internet formats.

What other Internet mail user behavior do you see changing because of IMAP?
In general, I find that hard to predict. People are very ingenious in finding new ways to apply technology. But one of the interesting areas is shared folders. With IMAP, users can change the access control list on one of their mail folders, so that others can access them. They can set the folder, for instance, to read-only, insert, write, that sort of thing. Managers can give their assistants read-only access to their mail, so the assistant can screen it and copy the mail into folders where the manager can then read the filtered mail. That's a big change.

What's next for IMAP?
Right now, most products are still coming up to speed on what can be done with IMAP4. In the next year or two, the IMAP community will be tackling localization and sorting, perhaps also a feature known as "annotation."

What's next for you?
I'll continue working on IMAP and Netscape Messaging Servers, but I'll also be doing some more work on Simple Authentication and Security Layer (SASL), the security framework I invented. It deals with legacy authentication systems and handles some things that are outside the scope of Secure Sockets Layer (SSL). Part of SASL is already implemented in Netscape products such as Communicator and Messaging Server, but we're going to apply it to more products.

"IMAP is great

for businesses,

because it

allows them to

centralize

their mail

storage. So

instead of

having to back

up mail on

hundreds of

PCs, the mail's

in a central

place."