The ACM Newsletter

Mumbai, February 2000

Internet Message Access Protocol

Hey! Tired of persistently downloading huge attachments in your mail using your normal POP server? Forced to download Spam? Disgusted with your mail server response time? Here's a solution to these problems: a standard, open and universal Internet protocol - IMAP (Internet Message Access Protocol).

POP (Post Office Protocol) is the most commonly used e-mail protocol but IMAP is the next really exciting wave to come crashing over the Internet beach. IMAP gives the power and advantages of LAN-based mail - but it works online, and you'll be able to access your mail from everywhere

What is IMAP?

IMAP is a method for accessing messages that are kept on a mail server. In other words, it permits a ěclientî email program to access remote message stores as if they were local.

IMAP is a robust protocol, giving users greater control while downloading mail to their machines. Only the headers of new mail messages are transferred, allowing users to decide which messages to download for reading. Mobile professionals on the road can save time by no longer having to download all their new mail at once. Instead they can download only the messages needing immediate attention and leave other messages, such as mail with large file attachments, for downloading at a more convenient time or when they return to the office network. Also, mobile professionals no longer need to carry all their mail with them or be concerned about losing messages during a network connection failure.

IMAP is a superset of POP that provides good support for all three modes of remote mailbox access: offline, online and disconnected. Unlike proprietary e-mail packages, there are no mail gateways involved; attachments get to their destination intact.

Implications of IMAP

Bandwidth saving

Our appetite for bandwidth is insatiable and saving valuable bandwidth is the need of the hour. With IMAP, when you check your mail, all you download is the headers: you don't download any message until you actually need to read it. No more waiting for attachments to download before you can read your mail.

Sharing Power

Mailboxes (mail folders) can be shared. Collaborating with co-workers becomes easy - no more rerouting, forwarding and confusion over multiple copies.

Messaging Integration

Everything in the message architecture can be integrated via IMAP: Usenet News can be fed into a shared folder and read as email. Mailing lists and mailing list digests work just like Usenet News. You can hold bulletin-board discussions with friends and co-workers.

Scalability and anywhere access to data

With IMAP combined with ACAP (Application Configuration Access Protocol), it's possible to store data in MIME and internet-mail message format on the network. Never bother about your bookmarks - keep them online for sharing and access on the road. Store data, to-do lists and schedules.

Characteristics common to both POP and IMAP

POP v/s IMAP Paradigms



IMAP has been called ěthe best-kept secret on the Internet.î The biggest problem with IMAP, it has been said, is that there are no good email clients that take advantage of it, but that is changing. IMAP is clearly the direction e-mail is heading.

References - Official IMAP site - Mulberry home page - Networking & Communications - Networking & Communications

– Venkatesh G. (


UNIX on Windows

As most of us know, there are many powerful and useful utilities available on the UNIX platform. However, if you are like me then you might be using a Windows machine at home, and perhaps at the office. It may be good thing to have UNIX and Windows both running on the same desktop. Well, you can have Linux and Windows on one machine; however, there is another interesting alternative. Let's have a UNIX environment running under Windows! I searched the Internet and was able to locate the following four software solutions:

  1. Cygwin from Cygnus
  2. UWIN from AT&T labs
  4. Microsoft INTERIX

Cygwin provides a standard UNIX/Linux shell environment for the Windows platform, along with a good collection of Open Source software. The cygwin.dll library, included with Cygwin, delivers a subset of UNIX SVR4, BSD and POSIX APIs to enable quick ports of UNIX/Linux applications to Windows. Cygwin is covered by the GNU Public Licence and only Open Source projects can be built and distributed with the cygwin.dll. If you are planning to develop commercial software then you will need to purchase it from Cygnus.

Cygwin is available on Windows NT 4.0 service patch 3. Its minimum requirements are a Pentium processor, 32 MB RAM and 100 MB free hard disk space. Binaries as well as source are freely downloadable from the company's FTP site. The company sells support and software on CD for a decent price. (

UWIN (ěUNIX for Windowsî) was developed by David Korn for AT&T labs. The UWIN package contains the following three elements:

  1. Libraries that provide the UNIX Application Programming Interface (API)
  2. Include files and development tools such as cc, yacc, lex and make
  3. The Korn Shell and over 200 utilities such as ls, sed, cp, stty etc.

This software is owned by AT&T laboratories. If you want to use it for educational, research and evaluation purposes then the UWIN binaries are available through the AT&T research web site at Commercial licenses for UWIN can be obtained from Global Technologies Ltd. or from Wipro International.

MKS NuTCRACKER Professional is claimed to be a complete UNIX development, interoperability and runtime environment on Windows. It implements all of the most frequently used commands, utilities and APIs of the UNIX 98 specification on both Windows NT and Windows 95/98. It then adds many frequently used platform-specific APIs, commands and utilities to provide greater compatibility with Linux, Solaris, HP-UX, AIX, IRIX, and legacy UNIX flavours (e.g. SUNOS). More details can be found at

Microsoft INTERIX offers the capabilities of UNIX systems on Windows NT. It includes an enhanced INTERIX subsystem for Windows NT and a comprehensive set of popular utilities and shells among other things. Its website is located at

If you plan to implement one of these solutions on your machine then don't forget to share your experiences with all of us!

– Shrikant Mulik (


Schedule of Upcoming Events

ACM General Meeting

February 11th 2000 - 6:30 p.m.
Venue: Lecture Theatre, NCST, Juhu