IMAP4 and the future of Corporate E-mail

Internet Standards Based E-Mail

Mark Fromm, from Seattle Sage Group topic on 1/09/97

IMAP 4: Standards based E-Mail

• Simple, Flexible, Manageable, Open-Standards based E-Mail
• Internet Message Access Protocol - Version 4 rev 1
• RFC 2060 - Mark Crispin - University of Washington - Dec, 1996

IMAP 4: Advantages, Attributes

• IMAP specifies how mail clients retrieve mail from mail servers
• You can leave copies of messages in the server - allows access from multiple machines, both remote over dial up and LAN based
• IMAP Allows for the hierarchy of remote folders - something POP has no provisions for.
• It supports automatic, bi-directional synchronization of local and remote folders and even shared folders.
• You can determine contents of a message without having to download the message, which is an important benefit when you're dealing with mail that contains multimedia attachments.
• Allows retrieval of individual portions of multipart MIME messages, as well as just the text portion describing the attachment. Valuable when performed over slow serial lines.
• You can search your mail folders at the server rather than be forced to keep a local copy of the entire message base. This capability minimizes the amount of data that must be transferred between server and client.
• Efficient mailbox access reduces network traffic
• Elimination of gateways to proprietary mail systems
• Single point mail server access allows single directory (address list) maintenance in 1000 person company - no e-mail directory syncronization headaches.
• Online, Offline, and Disconnected access
• Server Based Searches by sender, message text, subject etc. Minimizes network or dial up traffic. Fast and efficient
• Protocol is extensible - allows for future growth
• IMAP lets users set standard and user defined message status flags for messages, making it easier to keep track of what's been done with a message to date.
• Vendor and Operating Systems neutral, allows "Best of Breed" and "Best Fit" selections to be made for both Client and Server IMAP software
• An Internet open-standard mail client conforms to published Internet standards created by the Internet Engineering Task Force, the primary standards board for the Internet. These standards are open in that they are not controlled by one vendor and are widely published. The advantage of open mail is that you can use the mail client of your choice to access any standards-based mail server.

Recommendation

• IMAP4 E-Mail Clients/Servers instead of Proprietary E-Mail Systems
• This will result in:
• Simpler Day to Day Maintenance
• Less Administration Time
• Lower Base Hardware Costs
• Added Functionality
• Meet User E-Mail expectations / needs

Physio-Control E-mail Systems - Past, Present and Future:

(the past and present mail challenges at my company, with illustrations on how IMAP could simplify my life as an e-mail administrator)

Chart of Network and Server parameters - IMAP Mailbox access

This chart shows quite clearly how much more efficiently IMAP mailbox accesses are over the network or dialup

IMAP Information Links

www.imap.org - The Main IMAP Information page (UW) - the center of the IMAP universe.

Note the following sources for clients, servers, other tools and RFC' relating to IMAP

http://www.imap.org/products/servers.html

http://www.imap.org/products/clients.html

http://www.imap.org/products/others.html

http://www.imap.org/biblio.html (RFC's and drafts)

Source code and Binaries for various platforms, etc

Below you can get source code for IMAP4.1 beta, which compiled and installed for me quite painlessly on SunOS and Solaris. In addition, there is some older IMAP binaries (IMAP2bis with the PINE binaries) if you are too lazy to compile...

ftp://ftp.cac.washington.edu/imap/ (ftp sources for IMAP)

http://www.imap.org/whatsnew.html (IMAP in the press) - See what the Industry is saying about IMAP!

IMAP Clients and Servers you can try out!

http://www.sun.com/solstice/Networking-products/sims/index.html (Sun Solstice Internet Mail Server v2.0 ) This is a 60 day try and buy eval IMAP server deamon for Solaris.

http://www.download.com/PC/Result/TitleDetail/0,4,0-20708,00.html?cfeat (Netscape Communicator for Win95 - Has IMAP capability - but SEE MY NOTES later on this one!)

IMAP Troubleshooting

• Evil Win95 Networking: I had major headaches getting the Win 95 machines working properly for testing IMAP clients. (The NT and Solaris clients I tried were very straighforward to install). Seems there is some oddities that must be addressed. I could not get it to work, no way, no how, when I had "global" settings in the "dial up adapter - tcp-ip properties". As you may or may not be aware, in the Control Panels - Networks - Dial up tcpip passes global settings like DNS server, netmask, etc to all the dial up "connectoids" (an actual, honest, true Microsoft term) that use it. Many who have faced the frustration of getting Win95 Dial up PPP working, if they only connect to one ISP, set the configuration by the global settings. Others have similer settings between two dial ups, or are trying to pass a given DNS server when dialing up or connecting on the LAN. Well, it does not work. Your PPP and LAN connections can work fine for you, ftp, telnet, http, ping. You might have used it for months with no problem. But firing up the IMAP clients results in a crash of the winsock. Save yourself headaches, and clear the global settings. (write them down, as you will need them later). Reboot, or chant whatever it is that brings you luck on Win95, than config the "connectoids" (found in "Programs ; Accessories ; Dial Up Networking) and right click on a dial up selection to configure properties.
  
• Netscape Communicator: This was the new Beta Netscape (Nav3 has no IMAP) - but note the following problems I had with it. The first install I did was on a Win95 machine that had a version of Nav Gold3, and Communicator offered to install over it and take on it's settings. As my ISP offers IMAP mail access, and the Navigator3 had been configured to access my ISP account, I figured this would be pretty slick. However, after install, (and getting #1 above resolved) I still had no joy. I would get connection timed out, etc. I then installed Solaris IMAP mail server on the Solaris 2.5 Sun I have on my home network, and focused my efforts on getting the Win95 Netscape communicator talking to my Sun. Well, after a while, still no joy. I set up a "snoop" session to capture the packets and figure out what was going on. Examination revealed the Win95 Netscape Communicator trying TCP/IP port #110 (somethings wrong with this picture - should be #143 for IMAP). I figured I boneheaded out and left the Netscape client config for POP mail access. But NO - it WAS configured for IMAP! I spent some more time on it, and after checking Netscapes bugs and issues page, found that there were issues in "changing" any client mail properties after initial installation. (As is loaded over my original Navigator, which was POP, it took on those settings). So, I figured I would uninstall Communicator, remove all traces, and reinstall IMAP config first time. Problem #2 - The Netscape uninstaller did not work. I thought about trying to undo the 1000 registry changes, etc, and said screw it. I restored system from backups done prior to Netscape Communicator installation. (you do have backups, don't you??). Lessons learned on this IMAP Netscape Commicator Beta:
• Make sure no Netscape Navigator is currently installed and configured for POP mail access.
• Use an uninstallation monitor program to "watch" what Communicator does to your registry when it installs, so you can undo it. (Or restore from backups) 
• These glitches will surely be fixed in the production version, and may no longer be an issue by the time you read this.

• Sun's ROAM client (solaris, Win95, WinNT) - Works with the Sun IMAPD server as well as the IMAP4.1beta source I found on the UW IMAP ftp site and compiled on my Sun Mailserver. (Although it gripes that the 4.1 beta build is not the Sun IMAPD). The Sun ROAM does not look or feel like any Windows95 program (which is good or bad, depending on your view of the world.) Some Win 95 end users I had try it out hated the appearance, while the Sun users had no problems).

• Pronto Mail: This was listed and linked to the www.imap.org/clients page, and I downloaded "pronto96" for Win95 as a "try and buy timeout". After dinking with it a while, and not getting anywhere, I captured packets and found it was connecting to port #110 (POP) - not #143 (IMAP). Apparently, there is another client that is(?) IMAP, but you cannot see it without cash up front. Lesson leaned here: If troubles, Look at what port you are connecting to!

• Note that if you have a valid IMAP server, you should be able to telnet to port 143 and see IMAP greeting. To clean disconnect, type "0 logout". This will give you clues as to IMAP rev, etc host is running.

[mfromm] telnet mail.eskimo.com 143
Trying 204.122.16.4 ...
Connected to mail.eskimo.com.
Escape character is '^]'.
* OK mail.eskimo.com IMAP2bis Service 7.8(100) at Tue, 11 Jan1997 22:23:54 -080 0 (PST)
0 logout
* BYE mail.eskimo.com IMAP2bis server terminating connection 0 OK LOGOUT completed
Connection closed by foreign host.

• As the vendors stabilize the IMAP clients and server, the config glitches should dissapear into true interoperability (such as POP is today).

• Microsofts plans for Exchange and IMAP4: Well, they promised IMAP clients and servers in Exchange v 5.0. The problem arose when what was to be Exchange 4.1 was late, then renamed to 4.5, which got held up even more for bug cleanup, then finally named Exchange 5.0. IMAP is not supported in Exchange 5.0. So, I guess, we'll have to wait for version 7+ or(?) for IMAP. The Very First version of Microsoft Exchange was numbered version 4.0 so god only knows how the versions will come out. They are saying it will be released as a "service pack sometime"

Summary

I  have been using IMAP based email clients on Win95, NT and Solaris from numerous machines at work, a home, and on the run from laptops for a couple of months.

From a mail client access perspective, it has given me great flexibility and power in dealing with the crushing number of e-mail messages I receive. This includes user requests for systems work at Physio, system error messages, mailing lists, etc.

From an mail administrators standpoint, I can see that IMAP, internet standards based mail systems can dramatically simplify my mail administration life, while reducing support cost, system hardware costs, and increasing e-mail system reliability.