Managing IMAP

Foreword

For nearly 10 years after I invented IMAP, it was called “the best-kept secret in electronic messaging.” Then, around 1995, key electronic messaging software vendors became convinced of its advantages over the older Post Office Protocol (POP), and IMAP’s presence in the industry exploded.

Today, IMAP has evolved into a mature, widely deployed protocol. Even longtime proponents of POP have jumped on the IMAP bandwagon. More and more users are demanding IMAP, because IMAP is the only message access protocol that has the flexibility to accommodate their needs.

These users are part of a growing trend to access the Internet from a variety of different computers, appliances, and access paths. In one day, they may use a dialup from home; a wireless link on the bus, train, or ferry; and a super-high-capacity Internet2 link at the office. They may use a laptop while traveling and a desktop at home and work. They may be students using shared machines in a PC lab, with no personal data kept on the PC.

These users have more advanced needs for messaging than a single incoming mailbox that is periodically downloaded to a single computer. They may have a large archive of messages in a multitude of mailboxes that they need to reference at any time and in any place. They may participate in bulletin boards or other shared message collections (e.g., a shared “customer service” mailbox).

It could be any or all of the above. The common thread in these needs is highly diverse mail access patterns and needs. No matter how many different computers, network connections, or mailboxes one uses, IMAP offers the flexibility needed for effective access.

The trend is clear. The word is spreading to those email users who are not yet familiar with IMAP’s benefits. Corporate and ISP email providers are feeling the pressure to upgrade their services. Many server administrators, comfortable with a POP-only facility for many years, now find themselves playing catch-up.

Understanding the requirements of the task, much less planning how to do it, can be daunting. Fortunately, the “doing it” part is relatively painless once the way is pointed out.

Kevin and Dianna Mullet have done an outstanding job of presenting practical information on how to install, configure, and manage an IMAP server system. Both major freeware server implementations are covered in detail. I am particularly impressed by how the Mullets have uncovered and fleshed out useful information from mailing list folklore or passing mention in documenting.

A book like this has been needed for a long time. It belongs on every server administrator’s bookshelf.

Mark Crispin Seattle, Washington1 July 2000